If everything is working well right now, why is there a need to change it? New Zealand clearly isn't a hot spot for terrorism. GCSB is just a huge waste of money.
And what if you don't like someone looking at what you're doing? Just because you don't like being spyed on, doesn't mean there's something to hide. The same argument can be used about the government, as the saying apparently goes: "Evil is only done under the cover of darkness", transparency should go both ways.
It's the kind of archaic and draconian law which will simply not work. The people they are "really" after will be aware of this and will know how to hide from it.
Waste of money.