Definitely put your digital camera in your carry-on, as it's easy to swipe, even before all the extra security precautions. I have seen videos on those evening news programs that have caught baggage handlers opening luggage with keys and helping themselves to items. Not that it would happen often, but you don't need to worry about that, plus a digital camera is pretty small. Keys for standard luggage are probably pretty standard, not like a combination lock. But TSA might cut off combination locks if they need to inspect your luggage without your presence.