Kent Police are to pay compensation to three people who were unlawfully searched during a demonstration at a power station, lawyers have said.
Twins, then aged 11, and campaigner David Morris were attending a "climate camp" at Kingsnorth power station in 2008 when they were searched.
At the High Court in January, police admitted the searches were unlawful.
The solicitor who led the case called the police action a "massive violation of the human right to protest".
The twins, a boy and a girl who cannot be identified, and Mr Morris were among protesters who were processed through airport-style "checkpoints", their lawyers told the High Court.
They were taking part in the climate camp demonstration against plans for a new coal-fired facility at the power station near Hoo.
Lawyers for Kent Police told the High Court there had been a "misapplication of a clear policy by officers on the ground" which led to the unlawful searches.
Solicitor John Halford, acting for the demonstrators, said: "Kent Police has been forced to make a remarkable admission, thanks to this test case.
"It is that the outcome of one of the most expensive policing operations ever in the UK was a massive violation of the human right to protest."
Kent Police Assistant Chief Constable, Andy Adams, admitted on Thursday that "a number" of searches should not have happened at Kingsnorth.
But he added: "The publicly declared aim of some protesters was to break into Kingsnorth power station, an action which could have had the consequence of disrupting power supplies to a great number of people in Kent and could also have caused death or serious injury to anyone trespassing on the site.
"The police operation itself was very successful in preventing criminality and harm, while at the same time enabling a protest around an issue of genuine public concern to go ahead.
"We have accepted that many people were searched as a result of officer briefings which took place at the time of Climate Camp.
"A number of these searches should not have happened."
'Intimidation and violence'
The news of the payout comes after heavy criticism of Kent Police from demonstrators and politicians in the wake of the climate camp.
The Liberal Democrats claimed in a report that police had used sleep deprivation tactics and threatening behaviour to compile data on protesters.
And the then police minister, Vernon Coaker, apologised in the House of Commons for telling parliament that 70 officers were injured dealing with the protests.
His comments came after it was revealed that injuries Kent Police claimed had been sustained during the climate camp included insect stings, toothache and heat exhaustion.
It was also revealed that among items confiscated by officers during searches were a clown outfit, blankets, balloons and colouring books.
Sarah Horne, who took part in the climate camp, said: "We held a week-long public camp, packed with workshops, talks, action planning and demonstrations of sustainable living.
"We were met by a policing operation based on harassment, intimidation and violence.
"It wasn't just the unlawful searches - hundreds of people's possessions were seized, from walking sticks to crayons to health and safety supplies.
"This week, Kent Police have offered compensation to three people, but thousands of members of the public were searched, attacked or otherwise harassed at the 2008 camp.
"Are Kent Police going to compensate and apologise to them all?"