Obiter has just learned an intriguing fact about those irritating ‘I am not a robot’ puzzles on the sign-up pages for online services. The ones where you have to click all images containing a roadsign, a storefront or a car. It turns out that their purpose is not just to prove we are human but to make us unwitting participants in a gigantic crowdsourcing exercise.

It emerged at last week’s AI Congress in London that the puzzles are created by Recaptcha, a subsidiary of Google, as a way of collecting examples to train artificial intelligence algorithms to make decisions about fuzzy images. This ability will be essential for self-driving cars and other types of robot, which at the moment find it difficult to distinguish between, say, a bollard and a pedestrian about to step into the road. 

So, next time you struggle to figure out which of nine images contains a bit of a cat, remember you are doing it for the sake of technological progress. Well, for Google, anyway.