Our bartendress just 86ed a couple for the same--they were getting butts out of the ashtrays to smoke and finishing drinks left on the table. But they were also bothering the other patrons (besides grossing them out) for cigarettes and drinks. We also have non-spenders that aren't a nuisance that get helped. One guy drinks free coffee all night but he drives the drinkers home at the end of the night so he gets to stay.
There ARE people in our area who go to the casino shows for the free drinks and to try to win prizes to sell on Craigslist. But that fellow seems like something that is sort of fun and unusual as long as it's just one person doing it but if they got an influx, they would have to stop it.
Hard times. I, myself pretend to be a karaoke host so that I can get a free drink.......