Methods, systems, and apparatus, including computer programs encoded on computer storage media, for online fraud protection. One of the methods includes receiving a query associated with a user account of an online service provider; providing the query to a deep neural network model to generate a prediction of whether the user account is fraudulent, wherein the deep neural network model is trained using anonymized event data for a collection of users received from one or more online service providers; and providing the prediction to the online service provider.