its technically illegal for the banks and other methods of deposits to allow it, but technically its not illegal for you to play, is my understanding. if you want to hear more details, pm me.
the only thing that may suck, is that if we have a $10 tournament, people are more than likely just depositing for this (minimum deposit is probably 25 or 50 i would think). if you finish in 3rd you'd probably be getting something like $15 or $20 back depending on the number of people.
id be playing for fun and competiveness and not necessarily money, so its not a problem to me.