User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:42.0) Gecko/20100101 Firefox/42.0 Build ID: 20151110145223 Steps to reproduce: In preferences when you select Privacy -> accept cookies -> Keep until Actual results: Being presented with selection : - Until they expire (in this case you are agreeing to unlimited tracking, no limits set) - Until I close firefox (this sets a way too short lifespan for session cookies) - ask me any time (this option makes a lot of visual spam and it is really not a good choice, since most sites now want to set cookies). Expected results: To have one more choice - - Expire all cookies in <x> days. So cookies lifetime will be limited for a reasonable limit. If I set, for example, this option for 7 days: - my session cookies will mostly expire in less than this limit. - Long time tracking and forgotten visited sites that left long lived garbage cookies will be removed after a week.