Racketeering and extortion laws cannot be used against anti-abortion groups in the US, the Supreme Court has ruled.
The ruling applies to protests of all sorts
Protests of any kind could not be considered as extortionate if demonstrators did not "obtain" property of a targeted business, the court said in a majority judgement.
It overturned convictions of anti-abortion organisations who had been sued by pro-choice groups for illegally conspiring to use violence and intimidation to drive clinics out of business.
The decision lifts injunctions against Operation Rescue, its leader Joseph Scheidler and others who were barred from interfering with the businesses of abortion clinics for 10 years.
The racketeering action was launched by the National Organization for Women and other pro-choice campaigners.
They said they were fighting a conspiracy involving threats of physical violence and violent demonstrations around clinics, which constituted an effort to drive the centres out of business.
Racketeering and extortion laws are more commonly used against those involved in organised crime such as drug gangs or the Mafia.
ABORTION IN THE US
Abortion legalised by Supreme Court in landmark Roe v Wade case in 1973
1.3 million abortions in 2000, down from 1.6 million in 1990
21.3 abortions per 1,000 women nationwide
Number of providers fell from 2,042 in 1996 to 1,819 in 2000
33 states limit abortions for minors
The US' highest court ruled by a majority of eight to one, with Justice John Paul Stevens the only dissenter.
In the majority verdict, Chief Justice William H Rehnquist said if protesters do not obtain property they cannot be prosecuted under federal extortion laws.
The opinion comes after a 1998 decision which saw a jury in a lower court order anti-abortionists to pay about $258,000 in damages and not interfere with clinics for 10 years.
The ruling will also please other action groups, with actor Martin Sheen, animal rights activists and even some pro-choice groups believing protest should not be bracketed with extortion.
Chief Justice Rehnquist said it was not disputed that anti-abortionists had in some cases disrupted the business of clinics and even committed crimes.
"But even when their acts of interference and disruption achieved their ultimate goal of 'shutting down' a clinic that performed abortions, such acts did not constitute extortion," he wrote.
The ruling is the latest development in a legal fight that has been going on for nearly two decades.
Pro-choice activists have said they fear the current climate is shifting against them, particularly after the election of George W Bush as president.
The largely-pro life Republicans are also in control of Congress, and the Supreme Court is seen as having a majority of justices with Republican leanings.
President Bush has praised some pro-life campaigners and has said he would back a ban on the controversial "partial birth abortions".