If you use GMail, you can check your login activity to find out of someone else is signing into your account. Visit
(you need an account to see links) for info. To use this feature, scroll to the bottom of your inbox and click �Details� (very small in the far lower right hand corner of the screen). This will show you all currently active sessions as well as your recent login history. If you see active logins from unknown sources, you can force close them. If you see any logins in your history from places you don�t know, you may have been hacked. [Thanks Ken, I pasted your comment in here almost verbatim. Very helpful.]