It seems almost every activist group starts this way. Then people who are goal-oriented purposefully enter the group to slowly change its narrative, what the group is fighting for and why, slowly convincing them it's all about the greater good and all of their modern actions and beliefs stem from what they originally stood for. It's really almost cult-like when you think about it; in the undercover anti-fa videos, members have such a cult-like mentality of us vs them, with those who aren't enemies but not members of their ranks being "asleep", and them being the "savior". They can't see their hypocrisy, and don't question who's giving out the orders and funding their ops and if they even do think to question, they'll straight-up say on camera they don't care.

If someone is so convinced of a notion or objective to the point where they question nothing and it alters their perception and how they interact with reality, wouldn't you call that brainwashing? I know the FBI and CIA love to infiltrate movements, even silly, youthful, peaceful-music related ones; just look at the files they kept on John Lennon, Jim Morrison, The Kingsmen, etc (there literally are so many files on musicians it's ridiculous, so even fan-bases are "infiltrated" and musicians are "watched"). Unless you're keeping your movement underground and aren't letting any new people in, it's either going to get taken over eventually if it's making enough noise, or taken down.