Megaupload, one of the internet's largest file-sharing sites, has been shut down by officials in the US.
The site's founders have been charged with violating piracy laws.
Federal prosecutors have accused it of costing copyright holders more than $500m (£320m) in lost revenue. The firm says it was diligent in responding to complaints about pirated material.
The news came a day after anti-piracy law protests, but investigators said they were ordered two weeks ago.
The US Justice Department said that Megaupload's two co-founders Kim Dotcom, formerly known as Kim Schmitz, and Mathias Ortmann were arrested in Auckland, New Zealand along with two other employees of the business at the request of US officials. It added that three other defendants were still at large. link