Don't want people loitering where they shouldn't--subways, parking garages, in front of your store? Install the Mosquito, a device that emits a high-pitched whine that can annoy people enough to cause them to "move on".
Some people don't like it, though, and think the device should be regulated by "the authorities". Watch this video, and pay close attention to the woman who starts talking about 1:47 into it. Does this device seem like something that government needs to get involved with?
Government has a role--a very limited role. I truly don't understand those who want government's tentacles to reach into every nook and cranny of our lives.