European governments cannot force telecom firms to store all data - EU court
* EU court struck down EU-wide data retention law in 2014
* Britain and Sweden had challenged that ruling
* Targeted retention to fight serious crime allowed -court
EU countries cannot force telecom operators to keep all their customers' data, the EU's top court has ruled.
Attacks in Europe from France to Belgium - and, on Monday, in Berlin - have reinforced calls for security agencies to be given greater powers, while privacy advocates say mass retention of data is ineffective in the fight against such crimes.
The Court of Justice of the European Union (ECJ) said its ruling was based on the view that holding traffic and location data en masse allowed "very precise conclusions to be drawn concerning the private lives of the persons whose data has been retained".
Such interference with people's privacy could only be justified by the objective of fighting serious crime and access to data should be subject to prior review by a court or independent body except in urgent cases, it said.
The court was responding to challenges against data retention laws in Britain and Sweden on the grounds that they were no longer valid after the ECJ struck down an EU-wide data retention law in 2014.
A number of UK politicians had filed a legal challenge against a British surveillance law passed in 2014, part of which was suspended by a British court. British lawmakers subsequently passed an Investigatory Powers bill.
Similarly, Swedish telecoms operator Tele2 had told its regulator that it would stop retaining data after the ECJ struck down the EU Data Retention Directive.
The court also said that all data must be stored within the EU, given the risk of unlawful access.