The locations of the world's submarine fiber optic repair ships, 25 October 2010. Source
The global flows of digital information require submarine fiber optic linkages between continents. Since these cables are laid atop or just below the surface of the ocean floor, they are susceptible to being damaged by a number of sources, but primarily by fishing vessels dragging a net or anchor. Consequently, a fleet of cable repair ships sit ready in most major ports worldwide to mend a break. The 'x' is a sitting ship, and the triangles indicate moving ones. One could deduce most important cable routes as well as the places with regular problems by the clustering of 'x's and triangles. The English Channel, the Mediterranean, the Gulf of Oman, the Gulf of Aden, and the East China Sea. If a cable becomes damaged in a location without a cableship nearby, as happened to east Africa's Seacom cable in late July, the ICT linkages could be down for a while. Looking at this map, it seems that if a cable goes out in much of the Southern Hemisphere, unless a redundant link is in place, the affected regions could be without telecommunication linkages for a length of time, until a cableship is able to motor south to fix the outage.