I have heard some rare complaints about having something stolen but it was a situation where people left a safe open or something like that. I've left small amounts of money on the desk of my cabin and it was never touched. One nice aspect of cruising is one can leave everything valuable in the safe and only carry around their cruise card - that is you key to your room and the way one charges things. When I go off ship, I may carry one credit card and some cash but it is in one of my front pockets. In the long run, this should be the least of your worries, especially if you use common sense.