We are besieged with information every day, our inboxes overflow with spam and our search queries return a great deal of irrelevant information. In most cases there is no malicious intent, just simply too much information. However, if we consider active malicious entities, the picture darkens. Denial of information (DoI) attacks assail the human through their computer system and manifest themselves as attacks that target the human's perceptual, cognitive and motor capabilities. By exploiting these capabilities, attackers reduce the ability of humans to acquire and act upon desired information. Even if a traditional denial of service attack against a machine is not possible, the human utilizing the machine may still succumb to a DoI attack. Typically much more subtle (and potentially much more dangerous), DoI attacks can actively alter the decision making of humans, potentially without their knowledge. This talk explores denial of information attacks and countermeasures and uses network visualization scenarios to illustrate the problem.