I don't have any problem holding a merchant, even a mon&pop operation, to the terms they've agreed to. If they find iDine's terms too harsh, they don't have to participate -- most resturants don't.

In particular, offering a promotion and then acting as if the customer is a criminal for accepting the promotion is a real peeve of mine. I haven't encountered this with iDine (I don't mention I'm a member), but I have encountered it with Entertainment coupons and Priceline hotel stays.