For those wondering, I suspect (but cannot say with 100% confidence) that the filter you encountered was an attempt to halt the absurd amounts of spam that OCN has been subjected to in the past.
We generally have four or five robo-accounts that join and post 10-20 threads each about how you can "Watch XYZ soccer game live in HD" on their sketchy website.
You ban the accounts then they come back....
So I suspect that the message you're seeing is in response to that.
Edit and note: I am not a moderator or staff member. I'm just another guy