https://en.wikipedia.org/wiki/Th%C3%ADch_Qu%E1%BA%A3ng_%C4%90%E1%BB%A9c

Thích Quảng Đức was a Vietnamese Mahayana Buddhist monk who died by self-immolation (...) protesting against the persecution of Buddhists by the South Vietnamese government of Ngô Đình Diệm, a staunch Roman Catholic. Photographs of his self-immolation circulated around the world, drawing attention to the policies of the Diệm government. John F. Kennedy said of one photograph, "No news picture in history has generated so much emotion around the world as that one.

Calling them brainwashed is disrespectul and ignorant of similar acts that, while they haven't been enough to change policy, have invigorated social movements that sometimes resulted in the goals they were aiming for. The fact that you use "brainwashed" specifically almost makes me think that you can't even understand how people could see the murders of tens of thousands of children as something worth taking radical action for.