To PayPal, the transactions signal fraud: a U.S. user’s account is accessed in the U.K., China, and elsewhere around the world. But PayPal’s security system—thanks to a growing reliance on an artificial-­intelligence technology known as deep learning—is now able to spot possible fraud without making mistakes. That’s because algorithms mine data from the customer’s purchasing history—in addition to reviewing patterns of likely fraud stored in its databases—and can tell whether, for example, the suspect transactions were innocent actions of a globe-hopping pilot.

[...] I converted all 267 ads into a sequence of images, one per second, and fed them through the new Google Cloud Vision API. The Vision API uses Google’s deep learning algorithms to tag each image with the major objects, activities and themes it depicts, extract any recognizable text, estimate the geographic location it captures, and identify the presence and emotional expression of any human faces.