Despite what shitty movies claim from the second you pull into the parking lot and every place in between you are tracked and followed in any casino. You walk in with 20 pieces of luggage throughout the day you are going to get someone's attention. EDIT: AND I am 100% sure the MGM was in on it OR knew about it. They were probably told it was some kind of police sting operation or the FBI planning a big bust. The cops have offices at these hotels. There are two floors at the CNN building occupied by the US Army and plenty of alphabet fucks all over M$, Apple, and Google offices.