Fucking scumbag,
Master-p now this
I am pretty sure OP here uses some a simple bruteforing software like the notorious SentryMBA which is used to hack accounts. Programs like that require a wordlist of user:pass combinations to hack. If that's the case a simply making the password stronger will fix the security issue.
However it may be possible that he SQL-Injected the site or somehow got access to sensitive data on the Bitcointalk servers. I believe there was a hacker attack sometime last year on this forum and everyone got an email to change their passwords maybe the effects are just showing now. Theymos needs to check the servers for any security breaches ASAP.
Thank you OP for making this post, now the rules will be tightened and it will be harder for scammers to scam.