This is a very interesting article about the Internet. http://static-content.springer.com/image/art%3A10.1186%2F1471-2407-12-583/MediaObjects/12885_2012_3519_Fig2_HTML.jpg
http://static-content.springer.com/image/art%3A10.1186%2F1471-2407-12-583/MediaObjects/12885_2012_3519_Fig2_HTML.jpg