Lawyers for Kim Dotcom's associates say the judge who cleared their extradition to the US never gave them a fair hearing and the whole process was "off the rails".
The 42-year-old tech entrepreneur and his three co-accused - Mathias Ortmann, Finn Batato and Bram van der Kolk - on Monday began an appeal against a ruling last year that there was "overwhelming" evidence they had criminal charges to face in the US over their part in running file-sharing website Megaupload, and could be extradited.
Opening the appeal at the High Court at Auckland, Ortmann and Van der Kolk's lawyer Grant Illingworth described how the two were never given a chance to put up a real defence at the extradition hearing, because the US had seized their assets as "fugitives" and had blocked them from hiring any American experts.
The case needed to be stayed until the United States - where neither of the men had ever worked or lived - changed its policy, he said.
He said Judge Nevin Dawson - who cleared the extradition - had "failed to approached the hearing with an open mind".
"It's like ships passing in the night, with the radar switched off. The judge did not engage in a meaningful way with the arguments we presented."
Mr Illingworth said there was also a laundry list of issues about the way US and New Zealand authorities - including the GCSB and police - had exchanged information and gone about investigating and arresting the men.
"Those issues were not properly dealt with," he said.
Introducing his clients, he detailed how their lives had been torn apart by the case, describing Ortmann having his assets seized, and now kept apart from his partner in Germany - while, he said, Van der Kolk had been forced to delay having more children.
Earlier, Dotcom's lawyer Ron Mansfield lodged a request to allow the entire event to be live-streamed on video website YouTube.
He told Justice Murray Gilbert the hearing was fundamentally "a case of the internet age" and of huge global interest, meriting full coverage online.
But lawyers for the US opposed the application and the matter is set to be decided on later in the hearing.
Dotcom was in court, tweeting updates through the proceedings.
During the 10-week extradition hearing last year, lawyers for the US argued Dotcom and his associates had earned US$175 million (NZ$239m) by running a website funded largely by revenue from publishing copyright-infringing files.
The men have been locked in a legal battle since Dotcom was arrested in a raid on his Coatesville mansion in 2012.
The four face charges of 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.
If eventually extradited and found guilty in the US, they could be up for decades in jail.