On 23 September 2013 at 14:45, YouTube user Webdriver Torso quietly uploaded a video.

The mysterious 11-second sequence of red and blue rectangles could easily have been lost, unexplained and unappreciated among YouTube's plethora of kittens and music videos.

But 28 minutes later Webdriver uploaded an almost identical video, and another an hour after that, and another, until eight months later - apparently happy with nearly 80,000 clips - they fell silent, with 236 hours of video to their name.