No i dont think so. Its his fault for letting his password get out there. All thats required to log into something is a username and password. U didnt show someone a fake id u made of him or something.

1. They cannot prove YOU did it.
2. Theres nothing against the law about logging into someone elses stuff, as long as u didnt steal money or something.

No, u are not getting in trouble. Get on AIM and tell him to go fuck himself he cant touch u. Unless, hes really mad enough to drive over to ur house and kill you, which i doubt.

What exactly did u do may i ask?