Avoid the scam people who try to distract you by acting drugged out or drunk. They often work in twos: one person staggers around and bumps into you or your wife and then while you are distracted, the other one pick pockets either your wife's purse or your pocket! Just be aware and don't let them get near you. Also, do not put all your money or credit cards in the same place as your passport. Keep a little bit of cash and credit cards in multiple places. Just be on the lookout and you'll be fine!