In Joined Cases C-203/15 Tele2 Sverige AB v Post-och telestyrelsen and C-698/15 Secretary of State for the Home Department v Watson and Others  All ER 107, the Grand Chamber released its decision on the compatibility of mass data collection legislation in the UK and Sweden with European law.
Ever since the CJEU's Digital Rights Ireland decision, there has been uncertainty surrounding domestic legislation that provides for the collection and retention of, and access to, mass data. The EU Directive on privacy and electronic communications (Directive 2002/58/EC) allows member states to adopt legislation that limits the privacy measures put in place by the Directive in relation to mass data collection.
The Grand Chamber clarified the breadth of this discretion in its judgment. In particular, the Grand Chamber held that the Directive, when read in light of privacy and personal data rights under the EU Charter of Fundamental Rights, precludes national legislation providing for general and indiscriminate retention of all traffic and location data. Retention must be limited to what is strictly necessary, and this requires clear and precise rules within the legislation. The Grand Chamber further held that access to collected data must be restricted solely to fulfilling the purpose of fighting serious crime, and that access requires prior review by a court or independent authority. The Court was of the opinion that "while the effectiveness of the fight against serious crime, in particular organised crime and terrorism, may depend to a great extent on the use of modern investigation techniques, such an objective of general interest, however fundamental it may be, cannot in itself justify [the necessity of] national legislation providing for the general and indiscriminate retention of all traffic and location data."
The decision is a win for privacy advocates at the expense of broader indiscriminate powers to collect data in the fight against crime and terrorism.
See the Court's decision here.