Conceptual animation showing internet traffic, with normal data traffic white and malicious traffic red. Occasionally a connected server is taken down by a distributed denial-of-service attack, where a large number of typically virus-infected and remotely-controlled computers direct a huge amount of web traffic to a single site, overloading its servers and causing it to cease to function online. Such attacks are represented by the focus of red traffic on the southeastern USA early in the clip, and on eastern Australia midway through.