A Greek court, the Protodikeio Rethymnis, has lodged a request for a preliminary ruling by the European Court of Justice in the course of criminal proceedings. The Protodikeio Rethymnis wants to establish whether a national law on the groundless retention of communication data is compatible with the European Charter of Fundamental Rights. This follows a line of recent EU-wide judicial referrals and rulings on data retention. In March 2015, the constitutional courts of Bulgaria and the Netherlands had declared national laws on data retention unconstitutional.