AI-powered video technology is becoming ubiquitous, tracking our faces and bodies through stores, offices, and public spaces. In some countries the technology constitutes a powerful new layer of policing and government surveillance.

Fortunately, as some researchers from the Belgian university KU Leuven have just shown, you can often hide from an AI video system with the aid of a simple color printout.

Fool’s errand: The deception demonstrated by the Belgian team exploits what’s known as adversarial machine learning. Most computer vision relies on training a (convolutional) neural network to recognize different things by feeding it examples and tweaking its parameters until it classifies objects correctly. By feeding examples into a trained deep neural net and monitoring the output, it is possible to infer what types of images confuse or fool the system.

Eyes everywhere: The work is significant because AI is increasingly found in everyday surveillance cameras and software. It’s even being used to obviate the need for a checkout line in some experimental stores, including ones operated by Amazon. And in China the technology is emerging as a powerful new means of catching criminals as well as, more troublingly, tracking certain ethnic groups.