Facebook has sued a pair of Ukrainian men for developing and operating applications stylized as horoscopes and quizzes that illegally lifted users’ data.

The federal lawsuit, filed Friday in the Northern District of California, alleges Gleb Sluchevsky and Andrey Gorbachov were behind web applications that tricked users into installing “malicious” web extensions that allowed the defendants to scrape data from users’ social media profiles, and to place advertisements in their news feeds.