Please, tell us how paranoid you are about your personal data. We sure hope that your “spidey sense”, combined with two-factor authentication, automatic log-off and plenty of other precautionary measures are a part of your daily routine on the Internet. But what if you are responsible for the storage and security of data of hundreds, thousands, or even millions of your mobile users? In this article, we are going to speculate about the things that are huge for user data protection.