Police powers to use terror laws to stop and search people without grounds for suspicion are illegal, the European Court of Human Rights has ruled.
The Strasbourg court has been hearing a case involving two people stopped near an arms fair in London in 2003.
It said Kevin Gillan and Pennie Quinton’s right to respect for a private and family life had been violated.
It awarded them 33,850 euros (£30,400) to cover legal costs.
Section 44 of the Terrorism Act 2000 allows the home secretary to authorise police to make random searches in certain circumstances.
But the European Court of Human Rights said the people’s rights under Article 8 of the European Convention on Human Rights had been violated.
The court said the stop and search powers were “not sufficiently circumscribed” and there were not “adequate legal safeguards against abuse”.
The pair were both stopped outside the Defence Systems and Equipment International exhibition at the Excel Centre in London Docklands in 2003.
Mr Gillan, 32, from London, was detained by police for about 20 minutes as he was cycling to join the demonstration.
Ms Quentin, 39, a journalist from London, was in the area to film the protests. She said she felt she was detained for about 30 minutes, although police records said five.