Actually they have two excellent methods currently available. One is Directional frequency audible area denial that uses high frequency sound waves that will make you drop your weapon or whatever is in your hands and force you to cover your ears as you run in the opposite direction to try to get away from the pain. The other is a short wave radio beam that is also directional and causes a sensation of intense heat. Here again you run to get away from the heat. Neither is harmful to humans or animals. It just makes everything caught in the cone's focus extremely uncomfortable out to over 100 yards. That's a much better solution than truncheons, fire bombs, and water cannons where protesters are injured right along with the people attempting to do their job which is to protect lives and property from harm.