I think it's worth mentioning that this only applies to unmasking an ISP's customers, not individual website/social media users.
In common with the opposition that ruled out the use of DMCA subpoenas in the early RIAA case, the ISP argued that these subpoenas don’t apply to mere conduit providers, as defined under § 512(a) of the DMCA.
The Hawaii District Court agreed with Cox’s reasoning last year and quashed the subpoena. The ruling concluded that DMCA subpoenas typically don’t apply to DMCA §512(a) services, but do apply to other providers that store or link to infringing content directly.
I think the only real answer is going to be "it depends on too many factors people here can only LARP about really understanding, so ask a lawyer", and even then it still depends on what every individual judge in someone's case thinks.