Possible Duplicate:
How does SO's new auto-login feature work?

I've noticed that, even after I delete all cookies, Firefox Cache, Flash cache, etc. StackOverflow still knows who I am and automatically logs me in. It's a nice feature but if StackOverflow can do it, so can others. Where does StackOverflow store my login information on my computer on Firefox 3.6 / Windows 7?

  • I think the answer is HTML5 local storage. I don't know how it works on non-HTML5 browsers, though.
    – Gabe
    May 12 '11 at 19:11
  • Odd that clearing the cookies in Firefox didn't work for you; in my earlier tests that worked fine in Firefox and Chrome, just not in Safari. Or did you only delete specific cookies?
    – Arjan
    May 12 '11 at 19:30

Is it possible you are logged in with Google or Facebook or another service which is coupled to your Stackoverflow account?