Censorship... Such a beautiful thing, gives people time to think about life. Seriously, this is some 1984 BS. Also, if they are going to prevent you from posting it should say so before you start typing not when you go to submit.
To be fair, I've never had my comments censored in any way. I sometimes get the "you're posting too quick" message because I did upvote a couple comments in the previous few seconds, but trying again after a minute works for me. So I honestly haven't seen any automated censorship system you're talking about in my 11 years on this site.
Fair enough, however when I get the "you're posting too quick" message it can take upwards of 3 hours before I can post again... so I just stop trying and end up losing whatever response I composed beforehand.