An anti-espionage demonstration at the Waihopai spy base takes place on Saturday.
The surveillance spot has been operating for 30 years, and has been the subject of several protests and disputes. It's reportedly part of the US-led Echelon network, operated by the 'Five Eyes' countries - New Zealand, the US, Australia, Canada and the UK.
Green Party co-leader Marama Davidson will be speaking at the annual event for the first time, and is keen to meet others who turn out.
"We are grateful to however many people are able to have a voice, a strong voice on keeping us to account on the power of spying."
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She says the base represents a worrying culture of spying that is dangerous to our society.
"This is about governments being able to reach into our digital letterboxes, so to speak, and read all of our stuff. We've always been very, very clear - we've got to protect those freedoms."
The base has operated since 1989, and has always attracted controversy. Former Green Party member Keith Locke recently wrote about how Kiwi spies had kept eyes on him since he was only 11 years old, including during his time as an MP.
Ms Davidson says there's an alarming trend of digital information being intercepted by the state.
"We've got to always make sure we are inspecting, investigating and limiting the spying powers of any executive."
In 2008 three men were found not guilty of burglary and wilful damage after they broke in to the Waihopai spy base in 2008 and slashed one of its two inflatable domes. They said destroying the domes would save lives in Iraq, and were let off by the jury because it was for the "greater good".