http://spywarcbzke2e6skl7wjwtmmnrkslue24cld6kfcufjhhwxtceogmuad.onion/articles/firefox.html
There are similar services with better privacy policies, but in the end, they still store the things you view in "the cloud". A real privacy-based browser would not be integrated with them by default. Can be disabled in about:config [8] Automatic updates Not that bad compared to all of the above, I guess — but still installs something without your consent, with possible new privacy nightmares in there.