Sergei Nechaev. Read his wiki page. These people are possessed by demons.
"he [a revolutionary] has severed every link with the social order and with the entire civilized world; with the laws, good manners, conventions, and morality of that world. He is its merciless enemy and continues to inhabit it with only one purpose – to destroy it."
This is what drives socialists, do not be fooled, it is a deeply anti-human ideology.