A leak is a safety valve in society - and the Whaleoil hacker is a "decent and ethical person", Dirty Politics author Nicky Hager told a packed hall of people in Auckland last night.
Hager said the attack politics outlined in his book could be combatted by greater public engagement in democracy.
They included the Prime Minister's staff organising personal attacks through the blogger Cameron Slater.
The author was given a standing ovation welcome from the crowd of 350 people and a second of roaring applause after speaking at the Mt Eden War Memorial Hall.
"A leak is what you do when something important is going on that would not be found out otherwise," said Hager.