Yep, its always a tricky situation with ponzi schemes. That's why I think that bitcointalk should ban any ponzi scheme activity from this forums. More scams will just hurt the bitcoin reputation and image.
I assume that Bitcointalk doesn't ban scams intentionally because doing so could open them up to a lawsuit when they don't ban something that turns out to be a scam.
Would be nice to have more control over ponzi schemes or some sort of escrow done provided and only sites that have an escrow done ie middle man service are allowed to be listed. Any others, are subject to being closed or put into another section, where it is more risky and highlighted as high risk and another section with low, medium risk involved, as theirs middle man service that acts as a "backup Fund" and can payout if people lose deposits or x amount is available to be returned etc. But Bitcointalk support wont do that anytime soon.
Ponies wouldn't exist if they operated with escrow, ponzis are there so the operate can run with the bitcoins.
Escrow? Sure, you can't operate a ponzi scheme with escrow, but you can't operate a legitimate investment either.