Assume bad faith
To assume bad faith is important when dealing with vigilantes and vandals. If you do not, then, they will exploit your trust by waiting for a moment when you have foolishly given them some access or power over you, and then betray you.
When someone has been touched by Wikimedia corruption they don't get better fast. Believing in one echo chamber lie creates more echo chamber lying, then groupthink, then, sysop vigilantiism. Basically, people make themselves stupid by believing the sysop power structure, which they do to have less casual conflict. Gradually they consider the SVpov to be just "common sense" - then they pollute politics as usual with those foul beliefs.