The emergence of online social networks and the growing popularity of digital communication has resulted in an increasingly amount of information about individuals available on the Internet. Social network users are given the freedom to create complex digital identities, and enrich them with truthful or even fake personal information. However, this freedom has led to serious security and privacy incidents, due to the role users' identities play in establishing social and privacy settings. In this paper, we take a step toward a better understanding of online information exposure. Based on the detailed analysis of a sample of real-world data, we develop a deception model for online users. The model uses a game theoretic approach to characterizing a user's willingness to release, withhold or lie about information depending on the behavior of individuals within the user's circle of friends. In the model, we take into account both the heterogeneous nature of users and their different attitudes, as well as the different types of information they may expose online.