At the convention I'm attending this weekend, it came up that it's illegal in Virginia to wear masks/helmets in public. Not only is it illegal, but it's a
felony. A Class-6 Felony specifically, which is harsher than the class-1 misdemeanor you'd get for impersonating a cop, were you to do that.
This came up since apparently this weekend, a cop gave a warning to the "Umbrella Corporation" costumed folks here, and the Mandalorian Mercenaries said they've been hassled by cops as well.
Googling a little, I found this thread mentioning it, and they highlight some of the exceptions under the law, which include safety equipment (as part of a
profession), and holiday costumes (which means Halloween of course), or a masquerade ball, which you can see here:
http://www.fairfaxunderground.com/forum/read/2/34357/34444.htmlHere's the relevant part of the Virginia code:
http://law.justia.com/codes/virginia/2006/toc1802000/18.2-422.htmlThis is important to know, since we have helmets. If we do events off of renfaire grounds, this becomes an issue. And if you find a cop who's having a bad day, he may try to stick it to you.
I'm assuming other states may have similar provisions, so it may be worth looking into if you are active elsewhere.