One of the biggest ever web attacks - in which more than one terabit of data was fired at a website to knock it offline - has been reported. Web hosting company OVH said it had been attacked by a botnet (zombie army) of hacked devices such as webcams. The previous largest attack was thought to be one on security expert Brian Krebs' website which hit 620Gbps (gigabits per second). That was also thought to be mounted via a botnet of compromised smart devices.