Photographers have been stopped while taking pictures of landmarks
Professional and amateur photographers have gathered in London's Trafalgar Square to protest against terror stop and searches.
The photographers say police are intimidating people with cameras in tactics to target possible terrorists.
Last week the European Court of Human Rights ruled the power to stop people without suspicion was indiscriminate.
The government is appealing, saying it is vital to make cities a hostile place for any possible attacker.
Freelance photographer and writer Marc Vallee, who helped organise the protest, said: "It's quite surreal today but we are pleased with the support.
"It's quite obvious that professional photographers across the country are being searched because they are photographers not because they are suspicious.
"It's a common law right to take pictures in public places and we are here to show that."
The demonstration comes after a year of rising tensions between professional photographers and police over the exact scope of Section 44 of the Terrorism Act 2000.
This special stop and search power allows police in specifically designated areas to stop people without suspicion of wrongdoing in an attempt to make it difficult for potential attackers to move around.
It is used in some key areas of London and other cities or airports where counter-terrorism officers suspect that violent extremists may be looking for targets.
According to the latest available figures, some 36,000 people were stopped under the power between April and June last year.
But photographers say the practical effect has been that increasing numbers of people with cameras are being left intimidated, angry and afraid after being asked to account for their actions.
Shami Chakrabarti, director of human rights group Liberty, said it had warned of the dangers of blanket stop and search for a decade.
She said: "We have been completely vindicated by the Court of Human Rights and in the coming weeks MPs will have the chance to change this law. Let's hope they step up to their responsibilities."
A series of controversial incidents over the past year have included photographers being stopped while taking pictures of landmarks and public buildings.
A separate counter-terrorism law, which in theory restricts the rights to photograph police officers, has added to the tensions.
Advice to officers
Shortly before Christmas, Assistant Commissioner John Yates, the head of counter-terrorism at the Metropolitan Police, warned officers they risked losing public confidence if they did not use the Section 44 powers sensibly.
But last week the European Court of Human Rights ruled the entire law was illegal because it was indiscriminate rather than properly targeted at the threat.
The government is appealing against that ruling and the power remains in force in the meantime.
Chief Constable Craig Mackey, the Association of Chief Police Officers' (Acpo) spokesman on stop and search, said: "Acpo has stated previously that everyone - photographers, members of the media and the general public - has a right to take photographs and film in public places. That has not changed.
"It is the job of police officers out on the beat to be vigilant, to keep an eye out for any suspicious behaviour and to act accordingly.
"And there is no doubt that every day their vigilance stops crime. Used correctly, stop and search is a powerful tool that can help protect all our communities from terrorism. Protecting the public remains our priority."