Hello everyone, it’s your resident Private Browsing developer here! I’ll state it up front – the release of 15.0.1 was triggered by code I wrote that broke private browsing mode in significant, privacy-affecting ways. Ehsan and I fixed that for 15, 16, and 17 by backing out the problem code completely, but we’ve been working hard to fix it properly in Firefox 18 (currently in Nightly). This means that we want YOUR help to ensure that we haven’t subtly broken private browsing mode in nightly, and here’s how you can do that:
Take some time every day to clear your disk cache, then put your browser into private browsing mode. If you want to use it for traditionally-private things, that’s cool, it just may be slightly more embarrassing to thoroughly report bugs you encounter. What would be very helpful is if you could spend some time using your browser for regular, non-private things, and every so often open up about:cache and look through the entries in your disk cache. If you see any entry that looks like it came from one of the sites you were visiting, file a bug and CC :jdm and :ehsan. In fact, I will even accept comments on this post, or IRC pings, or emails, or whatever – these are important privacy failures that need to be addressed before FF 18 goes out the door. Do your part to make it unremarkable!