People use websites for several important tasks such as banking, shopping, entertainment, and paying their taxes. In doing so, they are required to share personal information with those sites. Users place a certain level of trust in the sites they share their data with. If that information fell into the wrong hands, it could be used to exploit users, for example by profiling them, targeting them with unwanted ads, or even stealing their identity or money....For example, if a site leaks a list of users' names and zip codes...comparison of that time to the time reported by the server might be useful...