My understanding is that they don’t… practically at all. But if compelled by a court to give your information, they could later learn that the information you provided was false. Or maybe someone reported you and they ask for some type of verification. Either way, it’s one of many tactics that can be used against someone, even if you only gave fake information to protect your own privacy.

Frivolous DMCAs have also been used to reveal identities of people someone didn’t like.