Is there any evidence that masks stop healthy people from acquiring the virus? I think everyone agrees that sick people should wear one to stop it from spreading.
I'm also not convinced that a mask stops you from touching your mouth. Some experts are saying that it will actually cause you to touch your face more, and if the mask is not waterproof (are N95 respirators waterproof?) after less than an hour of wear the humidity of your breath will have created a large wet patch directly covering your mouth and nose. Now any time you touch a surface and then readjust your mask, you're planting more bacteria and viruses directly on that wet patch.
I'm also not convinced that a mask stops you from touching your mouth. Some experts are saying that it will actually cause you to touch your face more, and if the mask is not waterproof (are N95 respirators waterproof?) after less than an hour of wear the humidity of your breath will have created a large wet patch directly covering your mouth and nose. Now any time you touch a surface and then readjust your mask, you're planting more bacteria and viruses directly on that wet patch.