But it's way more fun to say that the entire Hilton empire does it if someone had a single experience at one hotel!

For what it's worth, I believe nearly every hotel reservation includes this in their policies. Maybe the policy he agreed to was different.

"Guarantee Policy: There is a Credit Card required for this reservation. If you use a debit/credit card to check in, a hold may be placed on your card account for the full anticipated amount to be owed to the hotel, including estimated incidentals..."