I believe in most states wearing a mask to covers one face, if not for costume partys, itself is a felony to conceal of the identity of the person. So that of itself is a crime.
SHTF vs TEOTWAWKI you ask? SHTF, just some crap on the ceiling and walls, TEOTWAWKI end of the world as we know it. Orignally made by 9mm/®™©