US marshals have raided a Chinese hoverboard-maker's stand at the CES tech show in Las Vegas. The officials confiscated all the company's one-wheeled vehicles and took down its signs after a Silicon Valley-based rival filed a patent infringement claim. The case is set to return to court in a week's time. The Chinese firm, Changzhou First International Trade, told the BBC it did not believe it had broken the law. It claimed it had developed its hoverboard a long time ago and had hidden it until now to avoid it being copied by other Chinese firms. It added that this was the first time it had been involved in such an incident.

http://www.bbc.co.uk/news/technology-35259579