A Predator B unmanned aircraft lands after a mission in Texas in November. U.S. Customs and Border Protection uses the unmanned aircraft outfitted with powerful infrared cameras and sensitive radar to patrol U.S. borders. (Associated Press)

A Predator B unmanned aircraft lands after a mission in Texas in November. U.S. Customs and Border Protection uses the unmanned aircraft outfitted with powerful infrared cameras and sensitive radar to patrol U.S. borders. (Associated Press)