The Weather Underground was active in 70's. They were opposed to the Vietnam war and carried out political attacks and bombings. Some acts included blowing up a statue, throwing Molotov Cocktails at the house of a Supreme Court justice, setting off a bomb on the Senate site of the US Capitol, settings off a bomb in a women's bathroom in the Pentagon, etc.
They made a movie about the group: https://www.imdb.com/title/tt0343168/
Interesting to think about in context of US Capitol riot from last week.