Translation: Thompson and Clark is fishing for information.

Mr Preston puts it in even simpler terms.

"Situational awareness and keeping a rod in the water - to me they just seem like fancy terms for spying."

Mr Preston had certainly been persistent, sending emails almost daily - hundreds in total. He was protesting, fighting to get his claim settled.

Once, he shouted at the Southern Response chief executive.

"I'm stuck in an earthquake-damaged home with a family that wants to move on with their lives, and when your insurance company doesn't respond to you, there's actually nothing else you can do," he told Newshub.

He was also helping organise a group of claimants taking a legal case against Southern Response.

"That was really only my ever crime - educating people, organising for a class action," he said.

The exact spying tactics used by Thompson and Clark have been kept secret, but the organisation has previously been caught snooping on and even infiltrating environmental groups.

The spying came as a shock to Mr Preston's wife, Wendy.

"You don't know how they're spying on you. Is it someone looking at you? I mean, it seems silly to even say it.

"Is there something in your house? Are they following you around? Are they taking photographs of you? I don't know. What are they doing?"