Flamboyant Megaupload boss Kim Dotcom has vowed to lie low as he awaits a US attempt to extradite him from New Zealand, fearing a backlash after making a series of high-profile announcements.

Dotcom, who communicates publicly almost exclusively through his Twitter feed, unveiled plans last week to relaunch his file-sharing empire on January 20, the first anniversary of his arrest in Auckland on online piracy charges.

A few days later, he told his 150,000 followers that he planned to revive a $400 million plan to run a fibre-optic cable from the US west coast to New Zealand, which faltered when a business consortium failed for find backers.

A spin-off of the cable plan, Dotcom tweeted, would be "free broadband for all Kiwis".

Some commentators labelled the pledge a publicity stunt and Dotcom, who has enjoyed huge popularity in New Zealand pitching his US extradition case as a David-and-Goliath struggle, said he sensed a backlash looming.

In the past, he has said he ignored calls from his lawyers to limit his Twitter musings -- which cover topics ranging from the extradition case to the US election -- but indicated he was finally willing to heed their advice.

"As much as I enjoy keeping my followers informed, I have to tweet less. Dotcom media overload. #Backlash imminent," he tweeted late Monday.

The 38-year-old German national is free on bail in New Zealand ahead of an extradition hearing in March.

He faces up to 20 years jail if convicted of money laundering, racketeering, fraud and online copyright theft in a US court.

Dotcom insists he is innocent and free to start a new file-sharing venture dubbed Mega, which will run on the website www.me.ga -- .ga is the Internet domain associated with the west African nation Gabon.

Details of the new service are scant but a teaser website linked to www.me.ga said commonly used domains such as .com and .net were vulnerable to prosecution by US authorities.

It said the new site would also use state-of-the-art encryption methods that mean only users, not the site's administrators, know what they are uploading.

That would theoretically stop authorities from accusing administrators of knowingly aiding online piracy, the central allegation facing Dotcom in the Megaupload case.

The FBI and US Justice Department allege Megaupload sites netted more than $175 million in criminal proceeds and cost copyright owners more than $500 million by offering pirated copies of movies, TV shows and other content.

In September New Zealand secret agents were deemed to have acted "unlawfully" in the way in which they monitored Dotcom in the lead up to his arrest.