I've been searching a handfull of stays and have not seen this requirement anywhere new lately. There are some locations like Las Vegas where this has been common practice for a long time at some properties and not just Hilton ones. I have encountered it at other random properties. I've had some where they take your credit card at booking and say there is a deposit then they do not actually charge you the deposit then a few days before your stay they magically process the charge for the deposit.