It's called being an ass.
Back at another forum, we used to do that to each other all the time, to lock people out of their accounts for 15 min.
EDIT: I'm going to throw out another possibility. Someone got into the CF server. They got your CF username and password and email, searched google for your email being in use in other forums, and tried to use your username and password on other sites. And than they tried password variations.
Originally Posted by Kage
Ah don't worry. They didn't get that password, and that one for that forum was less protected than this one.