The Law Society says the acquittal of three men who attacked the Waihopai spy base has not set a legal precedent.

Adrian Leason, Sam Land and Catholic priest Peter Murnane had admitted deflating a 30-metre-high dome shielding a satellite dish at the spy base, near Blenheim, in 2008.

However, they argued they were acting to save the lives of others, including victims of the Iraq war.

The jury deliberated for two hours before finding them not guilty on Wednesday of charges of intentional damage and entering a property with intent to commit a crime.

Mr Land says the verdict is a landmark in New Zealand history and the three men are privileged to have been part of it.

Adrian Leason told Morning Report the three were confident of the legality of their actions.

Asked whether the decision would affect what other activist groups do, he said the judge and the prosecution made it clear that every trial is unique.

"This is no general ruling giving permission and this particular defence we used was very specific to a whole lot of unique variables.

"I think another activist in another situation would have to look at the merits of their own defence, case by case."

The convenor of the Law Society's criminal law sub-committee, Jonathan Krebs, says only judicial decisions have value as precedents, so the verdicts will not pave the way for others to carry out similar attacks.

Mr Krebs told Morning Report the defence used, known as claim of right, would normally be used in certain property cases where a person doesn't know a crime had been committed - such as purchasing an item which is later found to be stolen.

'Not in public interest'

The director of International Relations and Security Studies at Waikato University, Ron Smith, told Nine to Noon the decision was an abberation.

It was not in the public interest that such a flimsy defence would aquit someone of criminal damage which may be in excess of $1 million, Dr Smith said.

In summing up the case to jurors on Wednesday, Judge Stephen Harrop said if the men believed they were acting lawfully, even if they were mistaken in that belief, they must be acquitted.

The Crown Law Office has yet to announce whether it will appeal against the acquittal.

Protest groups consider verdict

Anti-abortion group Right to Life says it will seek legal counsel over what the decision means for other activists.

Save Animals from Exploitation director, Hans Kriek, says people in the animal rights movement may reconsider what they do in light of the decision.

"However, the people that did the actions at the base got off because they were seen to be helping people, and wheras with animal rights people, from my experience, certainly in the courts, that will be weighted far less."

Meanwhile, Father Murnane says he hopes his deeds will inspire people to think about justice, and that people are more important than war machines.