A world map of the Carna Botnet's measurements of some 460 million IP addresses that responded to ping requests in June and October 2012. IP addresses shouldn't be confused with individual computers online -- they can harbour a number of devices. The colors indicate worldwide Internet usage, from blue (less) to red (more). The most responses came from big cities such as Tokyo, Seoul, Paris, New York, Washington and Sao Paolo. Meanwhile, Central Africa, the Australian Outback and North Korea are almost dark.