Facebook has asked the Government for an exemption from a new spying law that could see its two million New Zealand users' messages subject to interception by the GCSB.
The United States internet giant's request is in its submission on the Telecommunications (Interception Capability and Security) Bill which is being considered by MPs.
The bill gives the Government the power to force internet companies such as Facebook, Google and Twitter to provide electronic spy agency the GCSB with access to New Zealanders' messages and other communications carried over their systems. At present that obligation rests only with telecommunications companies such as Telecom, Chorus and Vodafone.
Google and Microsoft have already come out against the bill.
In Facebook's submission, the company's Australasian head of policy, Mia Garlick, said the bill "needed to be clarified to ensure that it is beyond doubt that services such as Facebook that provide stored messaging services are not subject to this legislation".
Ms Garlick indicated Facebook regarded the bill's interception provisions as "blunt tools, which have the potential to infringe on civil liberties and constrain economic growth".
She said Facebook, which has more than two million Kiwi users, already co-operated with New Zealand law enforcement authorities, "making sure that we prioritise any cases where there is an imminent risk of death or bodily harm".
The Labour Party's IT spokeswoman, Clare Curran, said Facebook had indicated that being forced to open its users' private messages to surveillance would be "untenable" for the company.
"If that's an untenable situation for their business, does that mean Facebook might stop providing certain services in New Zealand - in which case what are the implications of that?"
The legislation is being considered as the GCSB's US equivalent and intelligence partner the National Security Agency (NSA) is under fire for widespread covert internet spying on its own citizens.
Facebook was recently reported as one of several leading internet companies from which the NSA secretly harvested huge amounts of user data.
Founder Mark Zuckerberg responded angrily to those reports, last month posting on his own Facebook page that his company "has never been part of any program to give the US or any other Government direct access to our servers".
"When Governments ask Facebook for data, we review each request carefully to make sure they always follow the correct processes and all applicable laws, and then only provide the information if it is required by law. We will continue fighting aggressively to keep your information safe and secure."
• Facebook says the GCSB should not be able to spy on its two million New Zealand users.
• The Telecommunications (Interception Capability and Security) Bill could allow that.
• Facebook says the new law could infringe on civil liberties and constrain economic growth.
• Like Google and Microsoft, Facebook warns the law could clash with its overseas legal obligations.