If you are running MT 3.14, please be aware that there is a vulnerability in mt-comments.cgi. Six Apart is aware and is working on a fix. Please stay tuned for an update.
MT-Blacklist -> Hijacked comments.cgi
UPDATE: I have turned off comments until this is resolved.
UPDATE: MT 3.15 has been released.
Movable Type Publishing Platform: Movable Type 3.15 released