My guess is that about 1/2 of 1% of "walks" are due to guests overstaying their reservation and the other 99.5% are due to hotels trying to maximize occupancy. It's a lousy deal-you're on the hook and they're not.

In the hotels' defense, they're reacting to the embedded right of many customers to cancel without charge up to 6pm on the day of check-in, since other than for true prepaids, the customer's payment obligation isn't locked in until then. The hotel knows some will cancel at the last minute and thus overbooks. Anyone who thinks all this is unintentional isn't being realistic. Lawsuits aren't practical since the nuisance factor is high but provable damages are likely not even equal to the filing fee at the courthouse. The best remedy, just like lousy airline service, is to post often on FT and other sites like Trip Advisor and let others know what they're in for. A hotel on TA with four or five reviews that describe a walk may see a drop in bookings and think again about their policies.

I've noticed in the last year or so that many, maybe even most, of the hotel offerings on the internet require a prepaid, non-cancelable reservation to get the best rates. I think walking someone with one of those, while not fraud, would be a contract breach.