It's been sixty years since writer Isaac Asimov dreamed up his laws governing robot behaviour. But the message still hasn't sunk in. Researchers in Thailand have developed a robot security guard that comes armed with a gun, and has no qualms about whom it shoots. Called "Roboguard", the gun-toting sentinel is designed as a cheap alternative to a human guard. It can be ordered to fire at will, or told to check first with a human via a secure Internet connection.