[dkubb]

Also, why don't they share the lists with each other? They don't need government help to do this.

If there are privacy issues then they could just share a list of hashes and if someone's legal name hashes to something on the list then you deny them.

[rafale]

In pure HN comment degeneracy: they could then claim to be victim of a hash collision and you won't be able to prove it while maintaining privacy.

Also a hash doesn't provide privacy in itself. It just make enumerating people in the database more difficult.