They need to be tightly controlled--kept on a short leash, as it were. In the context of the U.S. government, that "short leash" is the Constitution, and the very explicit limits it places on the federal government's power--power, remember, that is borrowed from the We the People. We know the consequences of allowing the government to slip that leash. And finally, if, despite all our efforts, government does become tyrannical, it must be put down, like a vicious dog. Hence guns, and the Second Amendment. And we must be humane about it--bring enough gun.