Hackers who attacked National Party-linked websites in protest against the GCSB Bill have had no thanks from spied-on internet mogul Kim Dotcom.



The group uploaded a video on YouTube in which they claimed they acted because Prime Minister John Key refused to listen to the protests and uproar over the "despicable piece of legislation".



But Dotcom this morning tweeted: "Dear Anonymous NZ, hacking National Party websites is just giving John Key a new excuse to pass the #GCSB bill (cybercrime). Please stop it."



Eleven National websites were down this morning, though the group claimed to have hacked 13.



The National Party's official website was online at 7.30am although a number of others including the websites of John Key, Bill English, Gerry Brownlee, Michael Woodhouse, Judith Collins and Simon Bridges were inaccessible.



Justice Minister Collins later said her website was back up and running after the cyber attack.



"It just shows you that these people have tremendous powers - that they are completely unregulated," she said.



"We don't even know who they are, and they wreak havoc not only in governments but also could do on private people's websites, their bank accounts [and] everything else."



Collins said the attacks showed there were cyber criminals out there.



Labour and Energy Minister Bridges, shrugged off the hacking of his site.



He joked that "hundreds and thousands of people who would have been looking at it daily now don't know what to do".



He had technical advice that it could take "some time" to fix the site "because it is quite a complex website with a lot of photos of me on it", he added.



Anonymous New Zealand's actions follow protests in 11 towns and cities at the weekend where thousands of people turned out to show their opposition to the bill which would extend the powers of the Government Communications Security Bill and allow it to spy on New Zealanders.



"It has come to our attention that the thousands that have marched against this bill has still not been enough to send John Key and Peter Dunne a message," the group said.



"John Key, make no mistake the majority of New Zealanders oppose this bill. Due to your own arrogance and your unwillingness to listen to the people we have decided to take direct action."



Anonymous said Key "should have expected us".



"We announced our solidarity with the GCSB protesters around the country," it said.



The websites would remain offline until National patched its web servers or withdrew the bill and apologised to those it had affected, including Dotcom, Anonymous said.



The bill is before Parliament and likely to pass with UnitedFuture MP Peter Dunne agreeing to support it, giving Key the numbers he needs to get it over the line.