In one message, Mr Dotcom said he was working with lawyers and the Electronic Frontier Foundation, which campaigns on digital rights issues, to get access to that seized data and return it to users.

BBC: Details emerge on sequel to Megaupload service

Megaupload, digital rights groups and the company left holding the data have called for it to be released to users.

BBC: Megaupload: Data access talks to begin on 26 April

Telefonica Digital Insights will offer companies and public sector bodies "analytical insights" based on users' anonymised location data.

BBC: Telefonica hopes 'big data' arm will revive fortunes