Who Is The Culprit??

Open comp, waiting for window, click streamyx, click google chrome, click fb, enter email, enter password, log in and... YOUR ACCOUNT HAS BEEN SUSPENDED

My expression after that is:(X.X) and what I can say is:ARGGHHHH!!!!! Ok2, come down for a secod. Lets read what happen actually. Situation is like this:

"Someone has log in your fb account using your password without your permission. We sure it is not you and we call this case as phising. Because of that, we ask you to recover back your account by following the methods below. Place the person log in is in U***** S*****"

Wow, now I know I am really famous at oversea.. lol (pasan jap) First my ym and now my fb.. It drive me crazy! So the only thing can do is recover back my account. But to do it is not that simple. Must use new password and makesure that password is really safe. So I end up change my password several time start from 3***** to k******* to k******* to k************ to k*************** and after the 5th time trying, at last my password is considered safe and my fb account is restored once again. But one question in my mind, who is the person responsible in hijack my account?? who is the culprit??