It's bad enough that just picking up a can of Coke in mini bar will trigger a charge, even if you put it back, in many hotels nowadays. But now, some hotels are putting trays of snacks on top of the mini bar, and charging if anything gets moved (they can tell because of a sensor attached to a scale in the tray). Even if there's a note explaining the fees nearby, I know I'd either knock the tray over, or pick something up, or do something to trigger a charge that I'd have to argue away later. For a fun discussion on this, visit this post on Gizmodo. My favorite comment was this one:
Thanks to the MiForum listserv for the pointer.