Is the crackdown on illegal filming content that difficult?

When you look at famous webhard sites, they are full of hidden camera videos in plain sight.
Is the police unable to catch them? Of course, it might be impossible for the police to monitor all illegal filming content in real-time, but since they are being distributed so openly like that, the sites could filter them and take legal action, or they could become aware through reports and tips from victims or third parties through various methods...