Do you often forget to logout your Facebook account? or do you consider it as the most difficult task? Whatever, leaving your Facebook account open while you don’t really use it is a big security issue. By doing so you may risk yourself into an embarrassing situation. (Also read: 8 tips to secure your Facebook account from Spammers and Hackers)
For a guaranteed logout you may use a Firefox add-on that automatically logs you out when you close the browser window or if your Facebook account is inactive for a particular amount of time.
Facebook Auto-Logout – Install for Firefox
Note: This Facebook Addon seems to be unavailable
* Once installed, the add-on logs you out and clears cookies when you close your browser window,
* It also logs you out when there is no activity for a particular period of time, by default it is 60 seconds. But if you feel 60 seconds is too soon, then you may alter the timing in extensions – options.