The system is totally abused now, you can make reservations to numerous places for same evening. If the online software is adequate it should cut the abuse but I guess there is no way of stopping making reservations in different names. Only way to cut abuse is take a minimal deposit, say $5/booking. Many would think twice then. Or make you register and have an account with credit card authorization only allowing 1 reservation per evening.
So many ways to cut abuse online, very difficult the current way imo.
Yes, I think credit card authorisation is a good idea like they do on some of the more popular meals. People always search for ways to cheat the system though. I have noticed that on these boards.