PGP was specifically created to combat this sort of legal threat. It is proof that encryption is ultimately controlled by individuals. The identity management is completely decentralization and it works over pretty much any medium.
It seems that the world has somehow forgotten the lesson. People can only see the centralized systems and don't realize that the problem they are trying to solve is not solvable in general. Encryption is unstoppable.
Average Joes routinely use PGP on the darknets. So we even have a good current example of how encryption used in crime can come in a form that this legislation is powerless against.
Encryption might be unstoppable but they can always just assign you an IPV6 address and encryption fingerprint that becomes your new online social security number that is required from the compiler on up.
Notarize your apps buddy and sign into your app account... ;)
The threat here is not against anonymity, it is against encryption.
You can make as many PGP identities as you want and associate them with any sort of identity you desire, so there might be a political point available with respect to anonymity as well in some situations.
It seems that the world has somehow forgotten the lesson. People can only see the centralized systems and don't realize that the problem they are trying to solve is not solvable in general. Encryption is unstoppable.
* https://en.wikipedia.org/wiki/Clipper_chip