You may be right, but I wouldn't underestimate them.
I agree. They are organized ("community organized", but think gangs as paramilitary organizations and you get the picture). Some have no qualms about shooting whatever crosses their muzzle, have been trained to hate from the cradle, and are skilled at mob action from incitement to active participation.
Social media networks are likely tools for command and control, and what may have seemed to be organic mob actions are likely well organized behind the scenes and being directed using those networks.
I can't think of equivalent organizations in lighter skinned demographics, because since the Clinton Era any equivalent organizations have been characterized as "White Supremacist/White Separatist Hate Groups", even if it was just a neighborhood watch group in a mostly Caucasian area.