Political campaigner John Catt won a Court of Appeal challenge today to have his records deleted from a secret database of so-called domestic extremists.
The pensioner from Brighton, East Sussex, who has no criminal record, was shocked when he discovered that police had clandestinely kept a detailed note of his presence on more than 55 demonstrations over a four-year period.
Mr Catt said in a statement: "I hope this judgment will bring an end to the abusive and intimidatory monitoring of peaceful protesters by police forces nationwide. Police surveillance of this kind only serves to undermine our democracy and deter lawful protest."
His lawyer, Mr Shamik Dutta of Bhatt Murphy Solicitors, said that the judgment "acts as a safeguard against the creeping criminalisation of peaceful protest."
Mr Catt originally went to the High Court after the Association of Chief Police Officers (Acpo) refused to permanently delete all the data retained about him.