Privacy International v Investigatory Powers Tribunal

A warrant under section 5 of the Intelligence Services Act 1994 must identify the property sufficiently clearly for its scope to be objectively ascertainable from the warrant itself. It may describe property by reference to devices, persons, premises, locations or changing circumstances. It must not leave executing officials to decide which persons or property fall within the warrant. The principle of legality and the common law’s aversion to general warrants require clear statutory language before fundamental rights may be overridden. The national-security context does not justify giving section 5 the widest possible construction. The warrant’s specification is distinct from the application and from the Secretary of State’s assessment of necessity and proportionality.

Privacy International sought judicial review of the Investigatory Powers Tribunal’s preliminary ruling on Issue 4, concerning whether section 5 of the Intelligence Services Act 1994 permitted thematic computer-hacking warrants covering classes of persons or property. The Tribunal held that property need only be adequately described and objectively ascertainable, and need not be limited to named individuals or existing property.

The claim followed earlier jurisdictional proceedings, in which the Supreme Court held that the High Court had jurisdiction to review Tribunal decisions for error of law. The claimant also sought permission to add a challenge concerning the pre-February 2015 Article 8 regime. The central issues were the proper construction of “specified” in section 5(2), the effect of the principle of legality, and whether the proposed additional ground should be heard.

1. Disposition. The Tribunal’s ruling on Issue 4 was quashed. The court declared that a section 5 warrant must be sufficiently specific for the property concerned to be objectively ascertainable on the face of the warrant. The Tribunal’s determination under section 68(4) of the Regulation of Investigatory Powers Act 2000 was remitted for reconsideration. Permission to amend the claim in relation to Issue 9 was refused.
2. Statutory construction. The court’s task was to ascertain Parliament’s intention from the statutory words read in their context and consistently with the statutory purpose. Evidence about the operational benefits or disadvantages of thematic warrants was not a legitimate interpretative aid. The national-security purpose of the 1994 Act did not authorise the court to confer the widest powers that the language might sustain.
3. Principle of legality. The common law treats freedom from general warrants and unauthorised searches of property as a fundamental right. A general warrant is one that leaves the executing official to exercise judgment about which individuals or property are to be targeted. That would constitute an unlawful delegation of the decision entrusted to the warrant-issuing authority. Clear words, or a necessary implication, are required before Parliament can override that principle.
4. Meaning of section 5. The word “specified” in section 5(2) does not mean “of a specified description”. The contrast with section 7(4) of the 1994 Act and with the detailed categories in sections 99–102 of the Investigatory Powers Act 2016 confirmed that Parliament deliberately maintained a narrower regime. The warrant, rather than merely the application, must identify the property within its scope and must not delegate that identification to GCHQ officers.
5. Application. Section 5 can cover serial-numbered devices, devices used by named persons, devices at specified premises, objectively identifiable diplomatic lists, and devices within a defined geographical area or location during the warrant period. A warrant covering the property of anyone engaged in an activity such as terrorism would be insufficiently specific. Membership of an organisation may be sufficient only where objectively ascertainable.
6. Issue 9. The proposed amendment was refused because it was raised more than four years after the alleged unlawfulness and concerned a regime materially replaced by the 2016 Act. The issue was historical only, and the court declined to rule on a state of affairs that had ceased to exist.

• Supreme Court: The jurisdictional appeal was allowed by a majority in [2019] UKSC 22; the High Court was held to have jurisdiction to review Tribunal decisions for error of law.
• Divisional Court: The Tribunal’s ruling on Issue 4 was quashed. A declaration was granted as to the required specificity of section 5 warrants, and the matter was remitted to the Tribunal.