First, there is nothing stopping a full legislative assault on end to end encryption, various such proposals have had traction recently in both the US and EU.

The lawyerly phrase is “knew or should have known.” It could be argued that now that this technology is feasible, failure to apply it is complicity.

Think about GDPR. Eventually homomorphic encryption is going to be at a point where “we need your data in the clear so we can do computations with it on the server” will cross from “failure to be on the bleeding edge of privacy research” to “careless and backwards.”