text: HOW did they steal money?  If you lost money, and this went across state lines you can involve the FBI.  How do you know they "hacked" your buddies computer?  Most likely he had a virus which was a keystroke logger, meaning anything typed was sent to the virus writer.  If you logged in then they got your password.  Best thign to do is try to log in to your account, when it fails do password recovery since you know the answers, unless they changed them.  Then contact yahoo through their help system.