I don't think that's true. A safe harbor can't make you liable for something, it can carve out a specific case where you are not liable. So the DCMA safe harb

I don't think that's true. A safe harbor can't make you liable for something, it can carve out a specific case where you are not liable. So the DCMA safe harbor could say that they are not liable if they never moderate. That would mean that by moderating they would give up their ability to claim safe harbor. It would not make them liable. Their liability would then be judged based on what they did (ie was their moderation negligent in some way).