The courts and proportionality¶

The European Convention on Human Rights Article 8 protects private life, home and correspondence, and sets the conditions for interfering with it: in accordance with law, necessary in a democratic society, and in pursuit of a legitimate aim such as national security, public safety, or the prevention of crime.

“Necessary in a democratic society” has been read by the European Court of Human Rights to require a pressing social need and a proportionate measure. The court has found violations in bulk-interception regimes, in Big Brother Watch v United Kingdom and Centrum för Rättvisa v Sweden, both decided by the Grand Chamber in 2021, holding that the safeguards in place were insufficient. The response from states has been consistent: revise the legislation to add the procedural elements the court required, while preserving the underlying capability. The capability does not disappear when a judgment arrives. It gets a new legal coat.

The Court of Justice of the EU has been the sharper constraint on data retention. It has repeatedly found blanket, indiscriminate retention of communications metadata incompatible with EU law: in Digital Rights Ireland (2014), which struck down the Data Retention Directive; in Tele2 and Watson (2016); and in La Quadrature du Net (2020), which permitted only targeted or otherwise safeguarded retention. Member states have repeatedly answered with narrowed but still extensive regimes, and the precise line between permitted and prohibited retention remains contested and litigated. Signals-intelligence collection, by contrast, stays largely classified and enabled by statute, under oversight that varies substantially in independence and rigour.

Last reviewed: 2026-07-08.