It is harmful because for one, now kids are not excercising and playing outside anymore. They do not get any real life social interaction, which often causes people to hermit crab. Also, now the kids are becoming jer ks, because now, they can do whatever they would like without anyone ever finding out who it was. It also messes up their backs, because when someone grabs an electronic, they get comfy and usually bend their backs and necks. That is about all I can say at this time, but I hope it helps.