Military helicopters use "show of force" vs. D.C. protesters

Military helicopters in Washington, D.C., on Monday used a wind-blowing tactic to disperse protest crowds, and videos posted to Twitter showed civilians shaking beneath the gusts.

• The "show-of-force" involves lowering a helicopter so close to the ground that it kicks up dirt and debris, driving targets away from the area. The N.Y. Times notes that it's often used by low-flying jets in combat zones.