As usual with Greek lawmaking, this is more a tactic to scare people and to use as a sledgehammer when the state wants to, rather than some grand scheme to force the population en masse to de-anonymize themselves. You have got to understand that Greece is undergoing democratic backsliding and was never a very strong rule or law state to begin with. Laws in Greece tend to be super strict but loosely enforced, which basically means the establishment, the police, the courts, can use them to throw the book at whomever they deem too dangerous. The Greek state is structurally incapable of being an actual totalitarian apparatus, but can be an effective authoritarian one when it needs to.