1. Flicker, http://www.flickr.com/
2. Facebook, https://www.facebook.com/
3. Cisco, Cisco Visual Networking Index: Forecast and Methodology, 2011–2016
4. BitTorrent, http://www.bittorrent.com/
5. eDonkey, http://en.wikipedia.org/wiki/Comparison_of_eDonkey_software