Delete third-party cookies when closing Firefox

[Anonymous]

Using Google Translator

Considering that Firefox blocks cross-site cookies by default and for certain reasons "may interfere with some websites" ALL third-party cookies are not blocked, but if when we close Firefox the third-party cookies will be deleted, I think it's a good idea for privacy reasons and for the sites to work
I know there are some prefs for this:
network.cookie.thirdparty.sessionOnly: true
network.cookie.thirdparty.nonsecureSessionOnly: true
but it would be better to have them enabled by default
and if it really messes up some sites or for questions of ad preferences, consider using cookie exceptions

[Jon]

Thanks for submitting an idea to the Mozilla Connect community! Your idea is now open to votes (aka kudos) and comments.

[Ra]

I am unable to use my internet British Bank until I remove all cookies from Firefox.

[pbz]

Rather than clearing 3rd-party cookies after every session we have opted for isolating them between sites via Total Cookie Protection. This provides strong cross-site protection while still maintaining good compatibility with websites. Clearing cookies may break sites.
You're right in that we do make exceptions when we detect certain behaviors like login-flows (which require cross-site cookies). If you don't like these exceptions you can turn all of it off via the `privacy.antitracking.enableWebcompat` pref. However, note that this disables all of our web compatibility features - it may cause websites to break!

If you're curious, here is a detailed technical description of our Total Cookie Protection exceptions / heuristics.