Internet
The Internet, also known as the world wide web, is one of the greatest technological innovations of the human race. Whether that is a good thing or not is a matter of personal opinion. It can be used to search for information, sell items in online auctions, and rip on people you've never seen before.
Just be careful what you put on it, as you may get attacked by a child molester...or the ultimate bad cop.
Fiction
Transformers (2007)
As part of his efforts to gain money to buy a car, Samuel James Witwicky tried to sell Archibald Amundsen Witwicky's equipment in an online autcion, including his telescope, his compass, and (for some reason) his glasses. Barricade and Frenzy later tracked down Sam through his eBay page.
Later, when Sam met the Autobots, Jazz greeted Sam and Mikaela Banes as "little bitches". When Sam asked how Jazz could talk like that, Optimus Prime explained that they had learned Human languages through the world wide web. Transformers