Games where the main factor is whether or not new "investors" join the game. Also any Bitcoin-denominated investment product with an APR of 15% or more, which are similarly risky even if they're not actually paying interest using investor deposits.
Would this description cover any real investments or non-ponzi gambling sites? Would it fail to cover any ponzis that have existed in the Bitcoin ecosystem?
Also, are any actual users of the Gambling section irritated by this, or are people just trying to hide this kind of game? Is anyone against the creation of this section?