- Definitions of the types of information
- What Firefox Sends to Websites
- Feature-by-Feature Description of Data Practices
- What Mozilla Does to Secure Data
- Government and Court Demands for Information
- Overview of Other Situations Involving Possibility of Data Disclosures
- Mozilla’s Approach to Data Retention
- How Mozilla Discloses Changes to this Policy
- How to Contact Mozilla about this Policy
- Appendix of Practices relating to Prior Versions of Firefox
Types of Information
“Personal Information” is information that you provide to us that personally identifies you, such as your name, phone number, or email address. Except as described below, Mozilla does not collect or require end-users of Firefox to provide Personal Information.
“Non-Personal Information” is information that cannot be directly associated with a specific person or entity. Non-Personal Information includes but is not limited to your computer’s configuration and the version of Firefox you use.
“Potentially Personal Information” is information that is Non-Personal Information in and of itself but that could be used in conjunction with other information to personally identify you. For example, Uniform Resource Locators (“URLs”) (the addresses of web pages) or Internet Protocol (“IP”) addresses (the addresses of computers on the Internet), which are Non-Personal Information in and of themselves, could be Personal Information when combined with Internet service provider (“ISP”) records.
“Aggregate Data” is information that is recorded about users and collected into groups so that it no longer reflects or references an individually identifiable user.
Information Firefox Sends to Websites and ISPs
Like other web browsers, Firefox sends Non-Personal and Potentially Personal Information to the websites you visit when requested by the website. This may include, e.g. the type of browser you are using, the type of device you are using (desktop, mobile, touch screen), your language preference, the referring site, and your IP address. If you are viewing a video, the buffering functionality of Firefox may allow the server hosting the video to determine which sections of the video you have actually played. This information may be logged by the websites you visit and the Internet Service Provider you are using. What information is logged and how that information is used depends on the policies of each of the websites you visit and the ISPs you use.
A cookie is information stored on your computer by a website you visit. Cookies often store your settings for a website, such as your preferred language or location. When you return to the site, Firefox sends back the cookies that belong to the site. This allows the site to present you with information customized to fit your needs. Cookies can store a wide range of information, including personally identifiable information (such as your name, home address, e-mail address, or telephone number). Because of their ability to store Personal Information, or references to such information, cookies can allow websites to track the online movements of particular individuals.
Firefox itself does not set any cookies on behalf of Mozilla.
By default, the activities of storing and sending cookies are invisible to you. However, you can change your Firefox settings to allow you to approve or deny cookie storage requests, delete stored cookies automatically when you close Firefox, and more. An article in our Firefox Knowledge Base gives you information about changing these preferences.
Interactive Product Features
One thing that makes Firefox so flexible is the ability for you to add various add-ons, extensions, and themes to Firefox, thereby creating a custom browser that fits your needs. The following features show how Firefox provides the ability both to obtain additional add- ons easily and to protect against potentially harmful add-ons.
Get Add-ons Page
Firefox offers a Get Add-ons page of the Add-ons Manager that features popular add-ons and displays personalized recommendations based on the add-ons you already have installed. This page can be accessed by clicking (or tapping on a mobile device) on the “Get Add-ons” tab of the Firefox Add-ons Manager. To display the personalized recommendations, Firefox sends certain information to Mozilla, including the list of add-ons you have installed, Firefox version information, and your IP address. This communication only happens when the Get Add-ons area is open and can be turned off at any time by following these instructions.
Add-on Information and Searches
In order to keep the information displayed to you about your installed add-ons up to date, Firefox communicates with Mozilla once a day to update add-on descriptions, home pages, download counts, screenshots, and ratings. This communication includes the list of add-ons you have installed, Firefox version information, how long it took Firefox to start up, and your IP address. You can turn off this functionality at any time by following these instructions.
If you enter keywords into the search field for the Add-ons Manager, those keywords will be sent to Mozilla in order to perform the search, along with Potentially Personal Information (such as IP address) normally transferred to perform such functionality.
Automated Update Service
Firefox’s automatic update feature periodically checks to see if an updated version of Firefox and installed add-ons are available from Mozilla.
This feature sends Non-Personal Information to Mozilla, including the version of Firefox you are using, build ID and target, update channel, your language preference, and your operating system. This feature also sends Potentially Personal Information to Mozilla in the form of your IP address and a cookie that contains a unique numeric value to distinguish individual Firefox installs. Mozilla uses this information to provide you with updated versions of Firefox and to understand the usage patterns of Firefox users. We use this information to improve our products and services and to support decision making regarding feature and capacity planning.
Mozilla does not collect or track any Personal Information or any information about the websites you visit, and Mozilla does not release the raw information we obtain from these Firefox features to the public. We may release reports containing Aggregate Data so that our global community can make better product and design decisions. To prevent Mozilla from obtaining this information, you can turn this feature off in Firefox’s preferences. An article in our Firefox Knowledge Base gives you information about changing your preferences in non-mobile versions of Firefox.
Firefox also offers a Blocklist feature. With this feature, once a day Firefox does a regularly scheduled, automatic check to see if you have any harmful add-ons or plug-ins installed. If so, this feature disables add-ons or plug-ins that Mozilla has determined contain known vulnerabilities or major user-facing issues or fatal bugs (e.g., Firefox crashes on startup or something causes an endless loop). You may view the current list of Blocklisted items. This feature sends Non-Personal Information to Mozilla, including the version of Firefox you are using, operating system version, build ID and target, update channel, and your language preference. This feature also sends Potentially Personal Information to Mozilla in the form of your IP address and a cookie. In addition, Mozilla also uses this feature to analyze Firefox usage patterns so we may improve our products and services, including planning features and capacity. Currently there is no basic user interface to disable the Blocklist feature. An article in our Firefox Knowledge Base explains how you may disable the Blocklist feature. Disabling the Blocklist feature is not recommended as it may result in using extensions known to be untrustworthy.
Crash-Reporting Feature (not applicable to Firefox for mobile)
Firefox 3.0 to present
For the current versions of Firefox, “Firefox Crash Reporter” is Firefox’s crash reporting feature. With this feature, you have the option to include Personal Information (including your email address), Potentially Personal Information (including your IP address and the URL of the site you were visiting when Firefox crashed), and a comment. Firefox Crash Reporter also sends a list of all add-ons that you were using at the time of the crash, the time since (i) the last crash, (ii) the last install, and (iii) the start-up of the program. For Firefox 3.0.0 – 3.0.5, Firefox Crash Reporter also collects Potentially Personal Information to Mozilla in the form of a unique alphanumeric value to distinguish individual Firefox installs. This value is not assigned to users of Firefox 3.0.6 and subsequent versions. Mozilla only makes Non-Personal Information (i.e., generic information about your computer, the stack trace, and any comment given by the user) available in the public reports available online at http://crash-stats.mozilla.com/.
Beginning with Firefox 3.5 and all versions of Firefox for mobile, Firefox offers a Location-Aware Feature, parts of which may be provided by third-party service providers.
You Elect to Use the Location-Aware Feature
This feature remains inoperative until you visit a website that requests your location and you choose to opt in to the feature. If you elect not to, nothing happens. Each time you visit such a website, Firefox asks you if you want it to provide the site with your current location. Additionally, you may elect to have Firefox remember your choice to allow or not allow the feature for each site. Any such election is domain specific. You are able to opt out at any time of having Firefox remember your choice, just like any other preference setting.
What Information Firefox Collects
If you choose to allow it, the Firefox Location-Aware Feature first collects one or more of the following relevant location markers: (i) location provided by a GPS device built into or attached to your computer or device and/or geolocation services provided by the operating system; (ii) the wifi routers closest to you; (iii) cell ids of the cell phone broadcast towers closest to you; (iv) the signal strength of nearby wireless access points and/or cell phone broadcast towers; and/or (v) your computer or device’s IP address. Next, it attempts to determine your location using these location markers. Any information Firefox uses, receives or sends as part of this Location-Aware Feature is not received by any Mozilla servers or by Mozilla. Firefox does not track or remember your location. Firefox does remember a random client identifier, the temporary ID assigned by our third party provider to process your request, for two weeks.
Transmission of Geolocation Information to Third Parties
If your computer or device has a GPS unit or your operating system provides geolocation services and you have elected to use the location aware feature, Firefox will send your location information directly to the requesting website. If not, Firefox will send the other information described above, plus your user agent information (e.g., version of Firefox you’re using) and a temporary client identifier, to a third party geolocation services provider. That provider can determine your approximate location from such data (e.g., convert a set of WiFi signal strengths into latitude and longitude). This information is sent by Firefox over an encrypted connection and no cookies are used. Neither the domain name nor the URL of the site you’re visiting is sent to our service providers. Our providers estimate your location and return it to Firefox. Firefox provides your location information to the webpage that made the request.
Restrictions on How Third Party Providers Use the Location Information Received
Third Party Privacy Policies
Please carefully consider any website or service provider's privacy practices before agreeing to share your location.
- Location-Aware Service Providers. For information on how our service providers use the location data sent by Firefox, see the privacy policies linked from our list of third-party service providers.
Panorama Feature (not applicable to Firefox for mobile)
Starting with Firefox 4, Firefox provides Panorama, which manages your tab experience. Your tab usage and names are not sent to Mozilla, but rather reside locally on your device. The first time you run Panorama, a video may be presented to you explaining Panorama. The video or web page is hosted by Mozilla so Mozilla receives your IP address and date and time of receiving the video.
Firefox Sync Feature
The Firefox Sync feature is included in versions of Firefox beginning with Version 4. Firefox Sync allows you to synchronize certain data between your computers, mobile phones, and other devices that have the Firefox browser installed, by utilizing the Firefox Sync Services. (You can also use Sync with a syncing service hosted on a non-Mozilla server set up by yourself or a third party, but in that case this policy doesn’t apply to your use of such syncing service.) Examples of data you can synchronize include browsing history, form history, bookmarks, saved passwords, preferences, and open tabs. This data (“Firefox Sync User Data”) is stored on, manipulated, and transmitted to and from Mozilla’s servers by means of your use of the Firefox Sync Services. Firefox Sync User Data is encrypted on your computer before it is sent to Mozilla’s servers, so it is not available to Mozilla in a readable form. Mozilla uses SSL/TLS technology to ensure your Firefox Sync User Data is encrypted during transit.
In order to utilize the Sync functionality you must register for the Firefox Sync Services. During registration you will need to provide your email address and create a username and password (collectively “Account Data”). Your Account Data will be encrypted using SSL/TLS for transit. Your password will be stored on our servers in an encrypted form called a hash. This form of encryption disguises your password on the server, but still allows us to authenticate you when you sign into the Firefox Sync Services. Certain versions of Sync also ask you to create a secret phrase. The secret phrase is stored on your computer and is not sent to the Firefox Sync servers or to Mozilla. Mozilla does not collect any other Personal Information through Firefox Sync.
Mozilla receives and uses the following Non-Personal and Potentially Personal Information for the purpose of providing and improving the Firefox Sync Services: IP address, username, date and time of accessing the Firefox Sync Services, user agent string information such as the type of client OS and Firefox version in use, and aggregated operational data such as access log data and how many bookmarks, history, or tabs users have collectively created and synced.
The Firefox Sync Services also receive the host names you have given your devices that you are syncing. These names are used to label your tabs within Firefox Sync. If you don’t want to share your devices’ names, you should consider naming your devices with fanciful names rather than your actual name. The information is transmitted using SSL. Currently, you can opt out of having your devices named in Firefox Sync by visiting the Firefox preferences pane or about:config.
You can disconnect from the Firefox Sync Services and have your Account Data and Firefox Sync User Data removed from our servers at any time. On your computer, go to the “Tools” menu, highlight “Sync,” and click “Disconnect.” Then go to https://services.mozilla.com/delete-account/, and submit the form to request deletion of your Account Data and Firefox Sync User Data from our servers. If you are transferring a synced device to another party (such as if you are sharing, reselling, or donating your laptop or phone) you may wish to disconnect and then remove your Sync data from your device to avoid sharing it with the device recipient.
Firefox’s Personas feature is a theme that lets you personalize the look of your browser.
When you apply a Persona to your browser, Mozilla collects your IP address, the date and time you applied the Persona to your browser, and the url you used to make the application as well as the url you were visiting immediately before that (known as the “referrer” url).
Creating a Custom Persona
If you are creating a Custom Persona for your own use, Mozilla does not collect any Personal Information.
Contributing a Design to the Personas Gallery
The Personas gallery is where you can browse all the available designs. If you contribute a design or image (each a “Persona”) to the Personas gallery, Mozilla collects the following Personal Information: (1) your username and (2) your email address. Your username will be used to attribute your Persona to you and will be publicly available on the Personas gallery. You do not have to provide your real name; you can use a nickname or avatar. Mozilla will not make your email address publicly available without your consent or share it with any third parties other than Mozilla’s service providers. Mozilla will use your email address only to contact you regarding your design or to provide any additional information that you elect or opt in to receive.
Personas’ Interactive Product Features
After you have selected your Persona, it is stored on your computer. Once per day the Personas service checks to see if your selected Persona has been updated. This feature sends the same information that web browsers typically transfer with any HTTP requests including user agent and your IP address.
We use this information to improve our products and services and to support decision making regarding feature and capacity planning. Mozilla is an open organization that believes in sharing as much information as possible about its products, its operations, and its associations. Accordingly, we may release public reports containing Aggregate Data so that our global community and Personas partners may make better product and design decisions. For example, we think it is good for users of Personas to know which are the most popular Personas and Personas designers to know how many times their Persona was downloaded.
Report Web Forgery Feature (not applicable to Firefox for mobile)
Usage Statistics (also known as Telemetry)
Beginning with version 7, Firefox includes functionality that sends Mozilla usage, performance, and responsiveness statistics about user interface features, memory, hardware configuration along with IP address.
This feature is turned off by default in general release versions of Firefox and Firefox Beta. In order to enable Aurora and Nightly testers to provide more efficient feedback, Usage Statistics are enabled by default on Aurora and Nightly. In either case, if this functionality is enabled, users can disable it in Firefox's Options/Preferences by simply deselecting the "Submit performance data" item.
Usage statistics are transmitted using SSL (a method of protecting data in transit) and help us improve future versions of Firefox. Once sent to Mozilla, usage statistics are stored in an aggregate form and made available to a broad range of developers, including both Mozilla employees and public contributors.
Firefox's default home page (<about:home>) loads small bits of information that we think will be useful to you. We call these "snippets". You can see them right below the search bar.
Once per day, Firefox gets new snippets from Mozilla. Whenever you see a snippet, that snippet makes a request to Mozilla, so that we can count how often snippets are viewed. This request to Mozilla sends the name of the snippet and is securely transmitted over HTTPS. Aside from this and standard log data collected as a part of any web request, snippets in Firefox do not send other information to Mozilla.
To help display relevant snippets, your Firefox browser sends Mozilla a monthly request to look up your location at a country level using your IP address. We then send that country level information back to your Firefox browser, where it's stored locally. Your Firefox browser (not our web servers) will then pick snippets to show you based on the locally stored country information.
Aside from providing you with the snippets service, we use the information from these requests to estimate what fraction of Firefox users click on each snippet (broken down into general categories like Firefox version and geographic area). We will not use any of the information in this request to attempt to identify you or your web browsing activity on other websites, and we aggregate the info we receive into these general categories as soon as is practical.
Feedback Button and Test Pilot for Beta UsersI
Firefox Health Report
Firefox Health Report (“FHR”) is a Firefox feature designed to provide you with insights about your browser’s stability and performance. FHR does this by collecting data and sharing it with us in a way designed to minimize our ability to identify your browser. Our systems aggregate your data with that of other Firefox users and then send it back to your browser so you can see how your Firefox performance compares to others. FHR does not send us sites from your browsing history.
We use the data sent through FHR to provide users with FHR’s functionality, such as helping you analyze and address performance issues with your browser. We also use what we learn from the FHR data in the aggregate to make Firefox and our other products better. We may disclose aggregated FHR data openly in order to help further our mission of promoting openness, innovation and opportunity on the Web. We aim to be transparent about FHR and you can learn more about the exact data being sent to us in the feature itself. If you wish, you can choose not to share your FHR data with us in Firefox settings or the feature itself. Learn more about FHR.
Mozilla is committed to protecting your personal information from unauthorized access, alteration, disclosure, or destruction. We undertake a range of security measures including physical access restraints, technical security monitoring, and internal security reviews of the environment. We also have policies in place to prohibit employees from viewing personal information without business justification. Additionally, it is our policy to ensure that Mozilla employees and contractors are bound by confidentiality obligations.
Beginning with Firefox 2.0, Mozilla has additional security features, some of which are provided by third-party service providers.
Secure Website Certificate Verification
When you visit a secure website, Firefox may check with any status provider mentioned in the certificate to validate that website’s certificate. Firefox sends only the certificate identification to the certificate provider, not the exact URL you are visiting. Sending these verification requests to third parties is sometimes necessary to ensure your connection to a site is secure; to help maintain your security, Firefox may block access to the site if it can't verify your connection using the third party. If the certificate is no longer valid, you will receive an error page that states why the certificate is not valid and you will not be able to access that website. The technical name for this process is OCSP or On-line Certificate Status Protocol. You may disable online certificate verification in Firefox's preferences under the encryption tab. If you do this, none of the information discussed here will be sent to any third party certificate provider. An article in our Firefox Knowledge Base gives you information about changing your preferences. However, if you choose to disable the online verification feature, Firefox will not be able to confirm the identity of the website you are visiting, which may put you at greater risk of having your private information intercepted. In this case, Firefox will also not show the identity of the website in the URL bar.
Protection Against Suspected Forgery and Attack Sites Features (not applicable to Firefox for mobile)
The Firefox forgery and attack protection feature displays a warning if the website you are visiting is suspected of impersonating a legitimate website (commonly referred to as a phishing or forgery website) or a site that infiltrates or damages a computer system without your informed consent, including, without limitation, any computer viruses, worms, trojan horses, spyware, computer contaminant and/or other malicious and unwanted software (commonly called an attack site or malware). By default, Firefox checks the web pages that you visit against a disallowed list that is downloaded to your hard drive at regularly scheduled intervals (e.g., approximately twice per hour), the rate of frequency may change from time to time. The disallowed list does not include the full URL of each suspicious site. Instead, each URL is hashed (obscured so it can't be read) and then broken into portions. Only a portion of each hashed URL is included on the disallowed list on your hard drive. If there is a match, Firefox will check with its third party provider to ensure that the website is still on the disallowed list. The information sent between Firefox and its third party provider(s) are hashed URLs. In fact, multiple hashed URLs are sent with the real hash so that the third party provider(s) will not know what site you are visiting. If there is a match, Firefox displays either a “Reported Web Forgery” or “Reported Attack Site” alert, as applicable.
You may completely turn off the forgery and/or attack site protection features in Firefox’s preferences. If you do this, none of the information discussed here will be downloaded to your hard drive or sent to any third party service provider. An article in our Firefox Knowledge Base gives you information about changing your preferences.
Each time Firefox checks in with a third party provider to download a new disallowed list, Non-Personal Information and Potentially Personal Information, such as the information that the browser sends every time you visit a website as well as the version number of the disallowed list on your system, is sent to a third party provider. In order to safeguard your privacy, Firefox will not transmit the complete URL of web pages that you visit to anyone other than Mozilla and its service providers. While it is possible that a third party service provider may determine the actual URL from the hashed URL sent, Mozilla’s policy is to require its third party service providers to enter into a written agreement with Mozilla not to use any data or other information about or from users of Firefox for purposes other than to provide and maintain their service. In addition, Mozilla’s policy is to prohibit these third party service providers from correlating any Firefox user data with any other data collected through other products, services or web properties of that provider. These third party service providers may post about additional notices regarding their applicable privacy policies. (For example, see Google Safe Browsing Service in Mozilla Firefox Version 3.)
Please note that we’re not yelling at you in this paragraph. Our lawyers have advised us that we need to make sure this information is conspicuous so you’ll read it. The forgery and attack site protection feature is provided “as is” and for your information as advice and guidance only. Mozilla and its contributors, licensors and partners do not guarantee that these protection features will prevent you from being deceived by a malicious website and we strongly recommend that you continue to be vigilant while online, particularly when following links sent to you in e-mail.
Legal Process and Other Disclosures
Consistent with our privacy commitments, we will scrutinize third party requests for information about you for compliance with the law, including those coming from governmental agencies or civil litigants. We may access, use, preserve or disclose information about you only when we have a good faith belief that it is reasonably necessary to do so to satisfy the applicable law, regulation, legal process or lawful governmental request of any country, or to protect the rights, property or safety of Mozilla, its users or the public. We will provide notice of legal process or governmental requests unless prohibited to do so by law or the circumstances warrant otherwise.
What and When We Share with Third Parties
Mozilla’s policy is to make Personal Information, such as your name and email address, and Potentially Personal Information, such as the URL of the site you last visited, only available to its employees, contractors, and selected contributors who signed confidentiality agreements that prohibit them from using or disclosing such information other than for approved Mozilla purposes.
We also work with third parties who provide infrastructure or back-end services (like content delivery networks, bandwidth providers, and services of an administrative nature). We may share Personal Information about you with such third parties for the purpose of enabling these third parties to provide such services.
Additionally, Mozilla may need to transfer Personal Information to an affiliate or successor in the event of a change of our corporate structure or status, such as in the event of a restructuring, sale, or bankruptcy.
Transfer of Data to the U.S.
Mozilla is a global organization and operates in different countries. Privacy laws and common practices vary from country to country. Some countries may provide for less legal protection of your personal data; others may provide more legal protection. By using Firefox, you consent to the transfer of the information collected, as outlined by this Policy, to Mozilla or its third party service providers in the United States, the Netherlands, and other places where our distributed, third party content delivery network exists (which is in several countries around the world), which countries may provide a lesser level of data security than in your country of residence.
We will retain any information collected for the period necessary to fulfill the purposes outlined in this Policy unless a longer retention period is required by law and/or regulations.
For More Information
You may request access, correction, or deletion of Personal Information or Potentially Personal Information, as permitted by law. We will seek to comply with such requests, provided that we have sufficient information to identify the Personal Information or Potentially Personal Information related to you.
Any such requests or other questions or concerns regarding this Policy and Mozilla's data protection practices should be addressed to:
Attn: Legal Notices - Privacy
2 Harrison St
San Francisco, CA 94105
Send us an email
Appendix for Pre-Firefox 4.0
Report Broken Website Feature. -3.6.x.
Firefox’s Report Broken Website feature lets you notify Mozilla when a website you visit improperly displays or incorrectly functions. The feature sends the URL of the broken website to Mozilla. You may also choose to send your email address and a description of the problem. This feature also sends your IP address and a variety of Non-Personal Information to Mozilla, including but not limited to the version of Firefox you are using and your language preference. Except for your email and IP address, Mozilla makes all of this information public. This feature does not send information to Mozilla until you explicitly authorize Firefox to do so. To prevent this public release of Personal and Potentially Personal Information, don’t report a website if the website’s URL contains your Personal and Potentially Personal Information, and don’t include Personal Information in your description of the problem. To prevent the release of any information, don’t use this feature to report a broken website.
Crash-Reporting Feature for Firefox 1.0-2.x.
For these earlier versions of Firefox, “Talkback” is Firefox’s crash reporting feature. Talkback also gives you the option to provide your Personal Information and Potentially Personal Information (including your name, email address, and the url you were visiting) and Potentially Personal Information (including your computer’s name, IP address, and the processes you were running at the time of the crash). You can selectively disable the sending of this information. Additionally, you have the option to include the URL of the site you were visiting when Firefox crashed, a comment, and your email address in the report. Mozilla only makes Non-Personal Information and Potentially Personal Information in the public reports available online at http://talkback-public.mozilla.org/.
Security for Firefox 2.0 to 2.x.
Protection Against Suspected Forgery Sites
The Firefox web forgery protection feature displays a warning if the website you are visiting is suspected of impersonating a legitimate website. Firefox lets you select various levels of protection, and different information is transmitted by Firefox depending on the level you choose.
By default, Firefox checks the web pages that you visit against a list of suspected web forgeries (a “disallowed list”) that is downloaded to your hard drive at regularly scheduled intervals (e.g., approximately twice per hour), the rate of frequency may change from time to time. If there is a match, Firefox displays a “Suspected Web Forgery” alert. Each time Firefox checks in with the third party provider to download a new disallowed list, Non-Personal Information and Potentially Personal Information, such as the information that the browser sends every time you visit a website as well as the version number of the disallowed list on your system, is sent to the third party provider. In order to safeguard your privacy, Firefox will not transmit the URL of web pages that you visit in this default mode to anyone other than Mozilla and its service providers.
You may completely turn off the web forgery protection feature in Firefox’s preferences. If you do this, none of the information discussed here will be downloaded to your hard drive or sent to any third party service provider.
Each time Firefox checks in with the third party provider to download a new disallowed list, Non-Personal Information and Potentially Personal Information, such as the information that the browser sends every time you visit a website as well as the version number of the disallowed list on your system, is sent to the third party provider. In order to safeguard your privacy, Firefox will not transmit the complete URL of web pages that you visit to anyone other than Mozilla and its service providers. While it is possible that a third party service provider may determine the actual URL from the hashed URL sent, Mozilla’s policy is to require its third party service providers to enter into a written agreement with Mozilla not to use any data or other information about or from users of Firefox for purposes other than to provide and maintain their service. In addition, Mozilla’s policy is to prohibit its third party service providers from correlating any Firefox user data with any other data collected through other products, services or web properties of that provider. These third party service providers may inform you about additional notices regarding their applicable privacy policies.