You can't restrict based on IP address since there are scenarios where a group of machines will present the same IP address. It's also very hard to verify with

You can't restrict based on IP address since there are scenarios where a group of machines will present the same IP address. It's also very hard to verify with other methods. They would have to take an approach similar to hotels or car rentals. Even then I don't think the problem is easily solved because if the demand is so great for these restaurants and the supply limited, charging or authorizing a payment ahead of time might not be much of a deterrent if the profits to be made are higher.