

In regards to your question about hidden methods to catch people, back before digital each film print sent to a theater had a unique “CAP Code” printed directly onto the 35mm film. This was a series of dots in a unique pattern that would show up several times on screen. So when a cam rip would show up somewhere this could be used to narrow down which theater it was recorded at and identify trends after several films.
I don’t know if this was ever successfully used to prosecute anyone though.
Until all coal plants are replaced there will be a need for more coal. We can’t just shut down these plants over night, the world is transitioning to cleaner energy production, unfortunately it’s just not happening fast enough.