Several parades roll in New Orleans on Sunday and most people camp out and make a day of it. Unlike parades in other cities, Mardi Gras parades require people to become participants. In fact, the crowd during Mardi Gras is as much a part of the action as the floats and bands. Throws are bead necklaces, doubloons, plastic cups, panties and lots of other stuff that are thrown to the crowd. People do all kinds of things to catch things.
Some people create elaborate nets with targets on a pole, other people show body parts.
It's all very entertaining. Anything goes when it comes to catching stuff. If you do, your hand is going to get stomped on. If a throw ends up on the street, quickly put your foot over it and when the crowd settles down, pick it up. It can be tempting to run out to catch throws from a passing float.