The big picture: At its peak, Megaupload reportedly accounted for four percent of all traffic on the Internet and had as many as 50 million daily visitors. Other services could just have easily been singled out in the crackdown against copyright infringement but Megaupload was an easy target.

Internet mogul Kim Dotcom has lost his latest attempt to avoid extradition to the US to face charges associated with the operation of now defunct file-sharing website Megaupload.

Ira Rothken, Dotcom's lawyer, said they are disappointed by the judgment from the New Zealand Court of Appeal. "We have now been to three courts, each with a different legal analysis," he said, noting that "one of which thought that there was no copyright infringement at all."

Rothken said Dotcom plans to appeal to the Supreme Court, the nation's highest court.

It's been more than six years since police raided Dotcom's Auckland mansion and took the larger than life Internet entrepreneur into custody. The Department of Justice said in a filing that Megaupload cost copyright owners more than $500 million in lost revenue and generated $175 million in income for its operators.

He was released on bail a month or so after his arrest but has been fighting legal battles ever since. If convicted in the US, Dotcom and his former colleagues - Mathias Ortmann, Bram van der Kolk and Finn Batato - face decades behind bars.

In a media statement, Dotcom said:

"As people will know, I am prepared to fight to get justice, whether it is for me or others. I will appeal to the Supreme Court. Just yesterday, the United Stated accepted that right exists. My legal team are confident that the Supreme Court will hear the appeal given there are such significant legal issues at stake. Many important cases in New Zealand are not won in the Court of Appeal, or in the Courts below, but are won when they reach the Supreme Court. My case will be one of them."