The European Court of Justice (ECJ) has effectively banned the general use of telecommunications data retention for combating crime across the European Union.

In a judgment delivered by the ECJ's Grand Chamber on Tuesday, the court ruled that when the objective is combating crime, "the general and indiscriminate retention of traffic and location data exceeds the limits of what is strictly necessary and cannot be considered to be justified within a democratic society".

"Criminal behaviour, even of a particularly serious nature, cannot be treated in the same way as a threat to national security."

Traffic data is defined in EU law as "any data processed for the purpose of the conveyance of a communication on an electronic communications network or for the billing thereof".

Location data is "any data processed in an electronic communications network or by an electronic communications service, indicating the geographic position of the terminal equipment of a user of a publicly available electronic communications service".

This is more or less the same as what has been called "metadata" in Australia's data retention debate.

The now-invalid Irish Communications (Retention of Data) Act 2011 required telecommunications providers to retain all metadata for two years, and make it available to the Garda