Conversations recorded between internet mogul Kim Dotcom and his three co-accused, discussing their fear of being caught and ways of creating "legitimate" spin-off companies, have been read out in court.
"At some point a judge will be convinced how evil we are ... We have to make ourselves invulnerable," Dotcom is quoted as saying in US evidence presented in Auckland District Court to have the four men extradited.
After more than three years of legal battles, including 10 postponements and two Supreme Court hearings, arguments in the Megaupload founder's US extradition case began on Thursday.
Opening the case for US authorities, Christine Gordon QC said the whole case could be boiled down to a single statement: "[They] were part of a conspiracy, they deliberately attracted copyright infringing material to their websites, deliberately preserved that material, deliberately took steps to profit from that material and made vast sums of money," she said.
She said the only thing novel about the case - contrary to the respondents' argument - was its scale.
Megaupload had deliberately used auditors to conceal copyright infringing material on the site and encouraged users to make multiple links to each illegal file to make them more difficult to take down, Ms Gordon said.
Dubbed the "Mega Conspiracy" by the FBI, US authorities allege Dotcom and his associates - Mathias Ortmann, Finn Batato and Bram van der Kolk - illegally made $US175 million from file storage website Megaupload and related sites.
If extradited and found guilty in the US, the four face charges that carry decades of jail time.
They include conspiracy to commit racketeering, conspiracy to commit money laundering, wire fraud and two kinds of criminal copyright infringement based on an FBI investigation going back to 2010.
Judge Nevin Dawson doesn't have to decide whether the four are guilty or not, only if they could be surrendered to the US to face charges there. The justice minister then makes a decision on the matter.
Ms Gordon said another person arrested over the same "conspiracy" had already pleaded guilty in the United States, and a judge there had deemed the case to be enough for a conviction.