Anarchism
Anarchism is a social and political movement dating back to the 19th century that rejects government, authority and most society systems beyond local cooperation. There are also numeous subsets or variations of anarchism. Anarchists in the U.S. have a long history that includes bombings and assassinations, although in recent decades, its violence has primarily taken the form of rioting and violence at public events, vandalism and destruction of police-related targets (as well as banks and other symbolic targets). There have been a couple of anarchist-related bomb plots as well. Anarchists have also traditionally been a significant component of antifa, but the two movements are often conflated due to black bloc street fighting tactics used by both.