FRIDAY FOTO (December 11, 2015

Crossed Lasers.

U.S. Navy photo by Petty Officer 3rd Class J.R. Pacheco

U.S. sailors train with the LA9/P laser hail and warning system on the fantail (rear deck) of the aircraft carrier USS Harry S. Truman in the Atlantic Ocean. The LA 9/P is a non-lethal, non-blinding way to get the attention of  intruders, warn them off and confuse them optically if they persist.

They have been used to hail, warn and deter people until their intent is determined at vehicle checkpoints.