I've noticed that a few of my Hotmail accounts got 'locked out' recently for to many password attempts. I don't have any viruses or anything so I don't really know how this happened.
This could mean 1 of 2 things.
1. You were drunk one night, forgot your password, spammed the password field with hate and forgot all about it.
2. You have used your hotmail address to join another site with a different password and others have gotten this information.