Although I would expect a bot could easily be coded to run their entire post history against google for matches.
Much harder than it sounds.
They could pay for this if they want to not get banned or pay for manual review. I dont expect most would mind paying 0.1 btc for review and keeping their account.
I still disagree with the premise that 1 in 1000 is ok, but if such criteria were implemented then yes, demanding a payment could be a good way to do it. Not going to happen though.
I mean we are talking 1 in 1000 posts. Not real ico pump teams and scammers fucking the board up.
The likelihood of someone plagiarizing only 1 in 1000 AND GETTING CAUGHT is so extremely low that it's just not worth debating. There are many more spamming issues that this forum is facing. The "1 in 1000" offences can be handled by theymos through the usual appeal process.