As may have noticed or not, I'm a Web developer/designer and I'm working on a small project. The Password Stealer.
You will be able to login and by doing that, send a link to your friends or your enemys telling them that if they loggon, they will be able to see who's blocking them on msn and things like that. After that, you will see their passwords on your account.
Of course the "main" purpose of this is to recover a stolen account or something like that