the book Direct Action: An Ethnography has some great insight into this but it's a real slog. the main tl;dr is that you organize in ways where it's very hard for one or two individuals to sabotage your group, whether it's a working group, general assembly, or affinity group

also, we've got to stay on our toes. permanent, above-ground political parties can't exactly carry out sustained illegal or violent operations except in moments of extreme crisis. it's just not on the table anymore because anyone connected is going to lose everything and go to jail forever. all the street action is going to have to be done by much more free-floating associations of people with only loose connections to parties, unions, or community groups