In a blog post, Facebook deputy general counsel Paul Grewal laid out how SCL came into possession of the user data. In 2015, Aleksandr Kogan, a psychology professor at the University of Cambridge, created an app named “thisisyourdigitallife” that promised to predict aspects of users’ personalities. About 270,000 people downloaded it and logged in through Facebook, giving Kogan access to information about their city of residence, Facebook content they had liked, and information about their friends. Kogan passed the data to SCL and a man named Christopher Wylie from a data harvesting firm known as Eunoia Technologies, in violation of Facebook rules that prevent app developers from giving away or selling users’ personal information. Facebook learned of the violation that year and removed his app from Facebook. It also asked Kogan and his associates to certify that they had destroyed the improperly collected data. Everyone said that they did. The suspension is not permanent, a Facebook spokesman said. But the suspended users would need to take unspecified steps to certify that they would comply with Facebook’s terms of service.