I know I've fully expected this to happen at some point. I also have a full size Aliens Pulse Rifle that has the digital ammo counter and weighs 22 lbs and is in fact an actual registered firearm that I had to order from the states (shoots those yellow pellet things) Technically you can be arrested for taking it out in public but my wife has used it as a part of a Ripley halloween costume several times and so far neither of us have been shot. SO FAR
But yeah my first thought when I read that was "Oh my god it's impossible to kneel or get on the ground in one of those costumes". If a cop asked me to do that I'd just stand there and get shot, it's not possible to kneel in that armor.