Mozilla has very clear, detailed privacy policies for all data it collects: https://www.mozilla.org/en-US/privacy/firefox/ https://www.mozilla.org/en-US/privac

Mozilla has very clear, detailed privacy policies for all data it collects: https://www.mozilla.org/en-US/privacy/firefox/ https://www.mozilla.org/en-US/privacy/firefox/ You can find more developer-focused information on Safe Browsing and Telemetry: https://wiki.mozilla.org/Safe_Browsing https://wiki.mozilla.org/Safe_Browsing https://wiki.mozilla.org/Telemetry https://wiki.mozilla.org/Telemetry My understanding of the Safe Browsing feature based on browsing the above is that a list of blacklisted URLs is downloaded to the client, this list is known phishing sites. > Use something like Palemoon and configure about:config a bit more and you should be fine. But be very skeptical of Mozilla claiming FF is some privacy enhancing tool. Keeping Firefox secure and making the right tradeoffs for collecting data to make the product better (like telemetry and crash reports) while avoiding using the data for nefarious purposes is a hard job, and I think Mozilla does it very well (disclaimer: I work there, and I see the way people treat and talk about users and their data). > Their plugins ecosystem is also a security nightmare... Assuming you mean extensions (aka Add-ons) - it is true that there isn't really a security model around classic Firefox extensions, which is one reason they are so powerful. The current form of Firefox extension is essentially the same as in the 1.0 days, and was intended to keep the browser slim and allow for new non-core features. Web Extensions are intended as the replacement, they are similar to (and largely compatible with) the current Chrome extension system: https://wiki.mozilla.org/WebExtensions https://wiki.mozilla.org/WebExtensions Firefox already does and will continue to support more APIs than Chrome does, to enable more powerful extensions such as Tree Style Tabs.