What cause would you protest even if it meant you would get arrested for doing it?

I do not know if news of the BART protest made it out of the Bay Area but many people some affiliated or organized by Anonymous(group) for freedom of speech violations, they believed BART did to stop a protest of police brutality in the killing of a homeless man. They try to enter, and sometimes succeed in doing so, BART and disrupting service, even thought they know they will be busted, and fined. What issue or cause are you so passionate about, you would get arrested and/or fined behind? Would you block the only road to a wild mustang culling? Chain yourself to bulldozers to try to save old growth redwoods? You have something else?