Hi what is Weather Underground Organization?

Hi I have heard all the terrorist organization except the Weather Underground Organization. I did google it but I have no idea why there action is or what this organization are fighting for. Thank you.|||They were a militant anarcho communist faction that planned bombings, kidnappings, and other violent acts against the govt and civilians. They targeted youth for membership knowing that kids were most likely to commit violence without thinking and be impressionable enough to accept their dogmas and rhetoric. Its founders were the extremists of the extremists. One calling for example was for youth to kill their parents as a way of overthrowing the social trappings of the family and thus leaving its members with only the paramilitary faction as family.