The Government is suing three men acquitted over an attack on the Waihopai spy base in Marlborough for the damage they caused.
A spokesperson for the Attorney-General says papers were filed in the High Court at Wellington this week on behalf of the Government Communications Security Bureau, which runs the base.
It is understood the claim is for $1 million.
The trio admitted deflating a 30-metre high protective dome with sickles near Blenheim in 2008 but were acquitted by a jury in March this year after successfully using the "claim of right" defence.
Dominican friar Peter Murnane, Adrian Leason and Sam Land argued their actions were justified by the greater good of saving lives in Iraq, and that the Waihopai base contributes to torture and war.
The Government has said it wants to see the defence removed or reformed.
Father Murnane says the Government risks making a fool of itself in trying to get money from them, as none have any great assets or income. Father Murnane is a pensioner and the other men are organic farmers.
He told Checkpoint none of the men would be able to pay $1 million if they lost the case. However, he is not fazed by the legal action, saying it will give the group another platform to voice their opinions.
Father Murnane estimates the cost of the damage to the spy base is closer to $200,000 and was only alerted to the Government's legal action through news reports.
Waste of taxpayers' money, say Greens
The Green Party says the Government's claim for damages against the men is a waste of taxpayers' money.
MP Keith Locke says the Crown case goes against a jury decision that found the men not guilty.
Mr Locke says it will be a "mickey mouse" case because the Government is not prepared to say what the spy base does.