Governments often try that kind of nonsense. Usually against organized crime, terrorism, child abuse.
But in the end it’s just used for the heavy crimes like copyright infringement
Ultimately the US government's key escrow fixation largely faded away, and it was never clear whether it would stand up in the courts, but it still shows up from time to time.
It's quite possible that this would conflict with the EU's can't-believe-it's-not-a-constitution (the Lisbon treaty) if passed, too; for a prior example see the defunct data retention directive, which was nuked by the ECJ: https://en.wikipedia.org/wiki/Data_Retention_Directive