The US Department of Defense authorized the Department of Homeland Security to test a military weapon that emits electromagnetic waves and causes an intense burning sensation in the skin, in order to develop methods for possible use at the border with Mexico • The system, which was designed to disperse a crowd without the use of lethal force, has never been used at the border • In the past, there were concerns about strong injuries, legal difficulties and danger to the lives of those who would try to escape from it