The question can be looked at another way:
Do you want some government agency collecting all your phone calls and emails, ready to be searched and re-read/re-played at a moment's notice?
I'd prefer that not to happen.
Happy for them to track individuals suspected of something, as long as they have a warrant. But a dragnet on everyone? That's Stasi/Gestapo stuff which doesn't belong in a democracy.
There is no threat of terrorism; the last terrorist act in NZ was in 1985 (Rainbow Warrior).
We should at least wait until Australia is attacked before we worry about ourselves being a target.