I plan on avoiding any melee's and having some distance between me and any crazies. If I end up in a crowd like that I have made several bad decisions that day, and I am going to quickly and quietly evacuate. I'd say if you really think you might end up in one then dress to blend in and go with the flow until you can sneak off. Hand to hand combat in the midst of 100's of people is a recipe for a hospital visit. It won't be like you are Sir William Wallace in Braveheart slicing through dozens of people. You will get bashed, slashed or gashed. Possibly seriously. Not for me. I am keeping some distance bewteen me and such folks.