Heh, happened to me in Baltimore as well (about a year ago), although it was at the Marriott Waterfront. I did take the key, and I did open it once to peek, but I never removed anything. The bogus bill was $35! To their credit, they did take it right off the bill, but that makes me wonder if they know they have a problem with shrinkage. As I recall, I even checked out at the desk that morning, but I can't remember if they reprinted my folio. I never saw it until an extra charge hit on my credit card. I suppose it's possible they had a different problem, just got the room number wrong or something.