In thwe wrong hands these lasers can do other sorts of damage. Two years ago, the oldest grandson (19 years) approached some idiot, who was having fun, in a crowded dance hall, playing with an illegal laser purchased while on holiday in Thailand. He politely asked him to put it away as it was dangerous. Did he switch it off or put it away? No way! He was so annoyed at having his fun interrupted that he smashed the laser into the face of my grandson causing a great deal of damage to many of his facial bones. He required extensive surgery, including a zig-zag cut from ear to ear over the top of his head to enable them to peel back all the skin on his face in order to get to the damaged bones in his nose, cheeks and eye sockets. He now has metal plates holding most bits together and at this time of year he's in agony because these metal plates get very old in minus degrees.