Or maybe you're fighting a fire, and need to stop rubberneckers from wandering into harm's way. Ever wished you could quickly close off a freeway so no cars can get by? Ever wanted to block off the scene of a dead body so that curious pedestrians couldn't tell who exactly shot them? Perhaps you just want to peacefully do some construction work, but oblivious drivers keep driving into your work zone.
Eventually, you need to do something to keep nosy bystanders out of your business.
people get shot, people get run over, things catch fire.
