This is the hardest part of running these kinda things. And is the main reason why I think many shut down. I hosted something similar and eventually shut it down after a phone call from the FBI about CSAM I missed.
It’s incredibly difficult, and a constant game of cat & mouse. No amount of automation is perfect and will only be effective for short periods of time. Do not underestimate the complexity of it, especially if you’re trying to run it legit which means you & your (financials|freedom|job|life) are on the line from (copyright lawsuits|legal repercussions|etc.). It only takes one fuckup — safe harbor laws mean nothing if a company wants to be a bully.