Masks are simply dangerous. The revreathing of Co2 causes a lot of people to become dizzy, the heat also makes it hard for breathing as exhaling cools the body as well as sweating. What of those people who open carry weapons? If they have a mask on it's considered a felony. Theft? With a mask on you cannot positively ID people. Masks prevent some particles, but for the most part only serve as nuisance. Wouldn't have the numbers gone down if the masks worked?