I had to look it up too (I don’t use Firefox).
Perhaps @rabcor was referring to Firefox’s telemetry data collection. I assembled this summary from Mozilla’s own Firefox privacy policy.
By default, Mozilla processes your Firefox personal data…
Firefox sends data about your interactions with Firefox to Mozilla:
- Your IP
- Number of open tabs
- Number of open windows
- Number of webpage visited
- Number and type of installed Firefox Add-ons
- Session length
- Firefox version and language
- Operating system
- Hardware configuration, memory
- Crash and error information including Firefox’s memory contents at the time of a crash, “which may contain data that identifies you or is otherwise sensitive to you”
- Active URL at the time of a crash
- Outcome of automated processes (like updates)
- “Safebrowsing, and activation” (what’s this?)
- The number of times Firefox suggests or displays specific content and interactions with that content.
- Detailed interaction data with Firefox Suggest, add-on recommendations, top sites, etc.
Search specific (Awesome Bar, Search Bar, new tab search):
- Interaction with Firefox search features and search partner referrals
- Number of searches per search partner
- Ad engagement (when, but not what)
- Category information about your search queries (given example, “sports, travel, food, etc”)
May be shared with Mozilla partners:
- Location data, such as country, region and county (but not IP)
- Keyword location search data (eg, a city name if specified in the search query)
- Firefox Suggest display times, position and clicks
- Basic information about unrecognised downloads to Google’s SafeBrowsing Service, including filename and URL.
If “Improve the Firefox Suggest Experience” is an active setting:
- Anything typed into the search bar can be sent to Mozilla and partners.
Source: