Kim Dotcom, whose extradition battle is continuing, spoke to Parliament's Intelligence and Security Select Committee today -- arguing against the extension of the GCSB's powers.
"The new GCSB bill demands an expansion of spying powers. This is poorly timed," he said.
Mr Dotcom received a formal apology from Prime Minister John Key after it was revealed the GCSB spied on him illegally. Addressing the committee, he called his fight "an injustice" and said he believed more New Zealanders had received the spy agency's attention.
"I suspect the real scope of the spying by the GCSB is bigger than what we know today," he said.
Mr Dotcom argued against the outsourcing of the agency's powers, but Mr Key claimed it made sense and followed Mr Dotcom's business model with MegaUpload.
"We cannot value human rights if we hand our information to a spy cloud."
Mr Dotcom and associate Bram van der Kolk's submission the proposed Bill was a "clear example of the type of state intelligence agency overreach".
They went on to say spying on New Zealanders is unwarranted without safeguards and the proposed expansion of the GCSB aren't justified. The submission says the passage of the Bill has been "unduly hasty".
"We believe more time should be taken for public debate and inquiry before this Bill is passed."
Earlier, former Green Party MP Keith Locke - who has previously claimed to have been spied upon by the Security Intelligence Service - told the select committee the GCSB spied on Chile and Mexico to help America in the lead-up to the Iraq War.
Mr Locke is arguing for more transparency from the Government's spy agency.
"The Government can't just continue to hide behind the smokescreen that I saw during the 12 years I was in Parliament," he said.
Vikram Kumar, the former head of Internet New Zealand, knows the GCSB's role well -- having worked alongside the agency several times.
"I have been very impressed with their professionalism, with their hard work and with the constraints in which they operate," he said, "Expanding the role of GCSB, particularly to economic well-being, is troubling."
Mr Kumar says the reason behind this is the term "economic well-being" could refer to a number of things, and a shortage of skilled staff in New Zealand.
"The GCSB mindset is essentially a spying mindset, because that's what they are [...] and now we are trying to make them into a police mindset," he said.
"We will be operating in an environment of suspicion, just as we see and in fact I'd say worse, than what we see in the US."
Internet New Zealand's Jordan Carter and Susan Chalmers spoke to the committee together. Mr Carter spoke of his concern any changes may have in the years to come.
"It needs to deal with people with less good motives and power in the future."
Ms Chalmers was one of many submitters who spoke on the issue of metadata.
Metadata is data which provides information about one or more aspects of data. A common example is a digital photograph, which can show how large it is, when it was taken, where it was taken and other data.
"Metadata in many situations could actually be more revealing than the actual conversations themselves," she said.