I don’t think I’ve seen anyone in this thread mention Telecines at all. It’s a machine that captures the video and audio from the film print directly to digital. A lot of good Cam rips were filmed from the projection booth, and could conceivably be done by a projectionist surreptitiously. Telecines though, required a large piece of equipment and time with a print outside of hours. Likely you’d need to be a manager or owner to get away with it, or have their blessing.
I remember the excitement of finding a Telecine for a movie in theatres rather than a Cam. It felt like striking gold. I bet the people releasing those in scene groups would be treated like gods back then.