Check out this story on .50-caliber rifles in The New Republic:

A .50-caliber sniper rifle, experts say, would be more than capable of shooting down an airliner as it took off or landed. Indeed, aimed properly, this weapon could be as effective as a shoulder-fired anti-aircraft missile...

and...

Fifty-caliber sniper rifles are a relatively new weapon, dating back to the 1980s. In World War II, the Browning machine gun, still popular today, fired .50-caliber bullets at a high rate of speed but with little accuracy. Equipped with telescopic sight, the modern .50-caliber rifle shoots bullets, one at a time, with equal power and vastly higher accuracy. Up to five feet long and weighing between 30 and 60 pounds, the gun fires six-inch-long, half-inch-wide bullets that can rip through a 3.5-inch manhole from 200 yards away. In addition to incendiary bullets, armor-piercing rounds are commercially available.

Now look, I'm a proponent of the 2nd Amendment, but as with any other right, the right to bear arms is not absolute.

We can't own silencers, or land mines, or tanks. As a citizen of the U.S. you can own a shotgun, but not a nuclear weapon (though if the NRA got their way, you might be able to). The point is, we draw the line.

Which side of the line should the weapon talked about in this article be on?