I am trying to recall the name of TV-series that was aired in the 70s (possibly only in selected European countries?). IIRC it was a French production. The bad guy was using some kind of mind control devices. He was gradually getting more and more people as followers to his pacifist ideology (it was the cold war era, and pacifism might have struck a chord even without mind control).
His modus operandi was to send a dozen or so (mind-controlled) cronies to surround a new victim. They would form a square around the helpless target, forcing him to walk into a building, where mind control devices were surgically installed.
The protagonists were trying to organize a resistance movement. IIRC they failed, as the bad guy had good intelligence about their plans.