WELLINGTON, New Zealand - March 18, 2010 - Three activists who admitted breaking into a Government spy base near Blenheim and slashing an inflatable plastic dome covering a satellite dish, have walked free.

Their defense - that they mounted the attack to prevent others suffering - has been successfully used by Iraq-war protesters overseas, but is thought to be a New Zealand first.

Schoolteacher Adrian Leason, 45, Dominican friar Peter Murnane, 69, and farmer Sam Land, 26, were charged with burglary and wilful damage at the Government Communications Security Bureau (GCSB) facility.

The prosecution said the trio cut their way through fences into the base on April 30, 2008, then slashed the plastic cover over a satellite dish with sickles.

The trio readily admitted attacking the base, but said they were driven by a belief that the satellite caused human suffering and their actions to shut it down, if only temporarily, were lawful.

A jury in the Wellington District Court took only two hours to acquit them of all charges yesterday.

A similar defense - known as the greater good defense - has been run by protesters in Britain, Ireland and Germany.

In 2006, a jury acquitted five peace campaigners who used an axe and hammers to cause US$2.5 million (NZ$3.5m) worth of damage to a United States Navy plane which was refueling in Shannon airport in 2003 on its way to Kuwait, to deliver supplies for use in the impending war.

In the U.S. last month anti-abortion campaigner Scott Roeder was convicted of murdering an abortion doctor after failing with a similar defense. His lawyers had argued for a lesser conviction because Roeder believed the killing was justified to save the lives of unborn children. The defense was thrown out by a judge.

Auckland lawyer Peter Williams, QC, did not know of the greater good defense being used here previously, but said it had been successful overseas.

"I would have thought it would have been looked at somewhat skeptically by the conservative New Zealand judiciary."

Wellington lawyer John Miller said in acquitting the men, the jury would have to have decided whether the men genuinely believed their actions would save lives, and if so, whether the force they used was reasonable.

"If you believe someone's in grave danger of suffering and you prick a balloon [at the spy base], that seems quite reasonable, given your subjective belief."

Outside court, Murnane, who represented himself throughout the trial, said the action taken by the group had been successful.

"We wanted, in going into Waihopai, to challenge these warfaring behaviors and I think we have done this," he said. "We have shown New Zealanders there is a U.S. spy base in our midst."

The friar had told the court at the beginning of the trial the trio felt strongly about the unspeakable evil caused by activities enabled by spy bases, like torture, war and use of weapons of mass destruction, like depleted uranium.

He said later he was "not entirely surprised" but still relieved by the not-guilty verdict.

"I had a gut feeling all along that we would get an acquittal – but you can't be sure of that."

Asked if he would do it again, he said he did not need to.

"The nation [now] knows much more about the spy base and the harm it does."

Fellow protester Adrian Leason said they "broke a law protecting plastic to uphold a law to protect human life".

A spokesman for Prime Minister John Key, who is also Minister for the SIS and the GCSB, said Key would not be commenting on the decision as it was an intelligence and security matter.

The U.S. Embassy also declined to comment.

Green Party foreign affairs spokesman Keith Locke said evidence presented at the trial showed that the Waihopai spy base was collecting intelligence to help the United States Government. "This included intelligence to help the United States prosecute the Iraq war, even though the New Zealand Government was opposed to that war," he said.

"I hope that the not-guilty verdict will help break down the blanket of secrecy that successive governments have imposed around the operations of the base, and its true purpose."