For a charity, you could choose a good cause that upsets assholes. So they have to donate money to the charity to prevent it from getting the money that was donated.
Edit: Wait, are we reinventing poker?
https://en.wikipedia.org/wiki/Bidding_fee_auction
For a charity, you could choose a good cause that upsets assholes. So they have to donate money to the charity to prevent it from getting the money that was donated.