User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:40.0) Gecko/20100101 Firefox/40.0 Build ID: 20150826023504 Steps to reproduce: Log into facebook, then logout and exit Firefox (privacy options are set to clear *everything* on exit, including offline website data) . Actual results: There is still data in storage/temporary/https+++www.facebook.com/asmjs, I can see asmjs ├── metadata ├── module13 ├── module14 └── module15 for a total of 3692K. There is indeed an awful lot of persistent data not cleared (even after exiting the browser and rebooting the whole system) . Even manually clearing history with time range set to "everything" and *all* items checked( including offline website data and site preferences) doesn't do anything to this data, it's still there. Expected results: Firefox should actually erase all storage data on exit if privacy options are set that way, and furthermore manually clearing this data should work too when the correct options are set. There should be no such data inside the profile.

I think this is a duplicate of bug 527667 and/or bug 1047098.