A good list of no-nos to be aware of at Mardi Gras.
Mardi Gras Moments: What Not to Do – Intelligent Travel Blog
4. Be wary of the scam artists! If someone approaches you with the question, “I bet you $100 I know where you got your shoes” or any question along those lines, do yourself a favor and do not wager! Even if you purchased your shoes on Mars, they will get you every time with the infamous answer: “on your feet.” And at that point you may feel obliged to pay, because technically they are correct, aren’t they? Sometimes it’s even common to be forced into a service, such as someone offering a shoeshine, and before you know it they are shining your shoes and demand immediate payment (even if you said “no thanks” loud and clear). Avoid these folks as much as possible. The more you stall, the higher the chance of being pushed into a bad situation. Just keep on moving.
The last part of this example actually happened to me in New Orleans. Granted, it was just a homeless guy who wanted me to take his picture, then asked for a buck in payment afterwards.