The Internet is like the old Post Office adage, "Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds." However, when discussing the reliability of the Internet it looks like we can replace light weather events with the apocalyptic natural disasters that have consumed Japan this last week. According to the folks at Renesys, who have been reporting on the major Internet outages these past few months, including the political unrest in Egypt and Libya, the earthquake in Japan caused a 25GB/second drop in traffic, but that that traffic returned to near normal levels by the end of the first day. That's astounding.
There will, of course, be many connectivity glitches and malfunctions for some time, but the nation's Internet-based infrastructure withstood just about the worst nature has ever hit modern man.
What's particularly remarkable is the contrast between Japan's network disruption and the disruptions in Egypt and Libya, which were intentional, man made, and much more effective at cutting people off from the Internet. That adds a whole new dimension to concerns about Net Neutrality and the Internet Kill Switch being discussed in Congress. While nature and nuclear bombs can't easily break the Internet, man can break it pretty easily, and we now have the three recent events to prove it. In no case have we yet proven, however, that killing off Internet access is beneficial to anyone but those who seek to manipulate others.