it is likely that target rank was been move down from Ledgendary, Hero Member and Senior Member to Full Member (since last week).
I hardly believe there is a target like this.
IMHO the only bottleneck is scanning messages, which seems to be done section by section. If it was historically, no newbies would be banned at first.
Since the bottleneck isn't the resources needed by the bot to actually process the messages, it only means most high ranking members cheating a long time ago have been caught already, which seems logical if they plagiarized a lot. You can't ban a user twice
