“You probably haven’t heard of HD Moore, but up to a few weeks ago every Internet device in the world, perhaps including some in your own home, was contacted roughly three times a day by a stack of computers that sit overheating his spare room. In February last year he decided to carry out a personal census of every device on the Internet as a hobby. ‘[It] drew quite a lot of complaints, hate mail, and calls from law enforcement,’ he says. But the data collected has revealed some serious security problems, and exposed some vulnerable business and industrial systems of a kind used to control everything from traffic lights to power infrastructure.”
http://www.technologyreview.com/news/514066/what-happened-when-one-man-pinged-the-whole-internet/