Kim Dotcom may sue Twitter, Google, Facebook over copyright

Ex-Hong Kong resident and flamboyant internet mogul Kim Dotcom said he was considering legal action against tech giants such as Twitter, Google and Facebook for infringing copyright on a security measure he invented.

Dotcom, who is on bail in New Zealand as US authorities seek his extradition in the world's biggest copyright case, said he invented "two-factor authentication", which has been adopted by many major websites.

Twitter became the latest major player to introduce the measure on Wednesday following a series of cyberattacks that saw hackers take over the accounts of high-profile targets such as media organisations and send out fake tweets.

"Twitter introduces Two-Step-Authentication. Using my invention. But they won't even verify my Twitter account?!" Dotcom tweeted. "Google, Facebook, Twitter, Citibank, etc. offer Two-Step-Authentication. Massive [intellectual property] infringement by US companies. My innovation. My patent."