The recent earthquakes and resulting tsunami that hit Japan damaged the many nuclear reactor's that powered the country.
This has led to a loss of power for millions of Japanese inhabitants, in addition to the terrible loss of life and property.
Currently, Japan is doing all they can do to supply power where needed and that includes having rolling blackouts where power to a certain portion of the population is cut-off for a specific period of time and then turned back on.
Two video game developers, Square Enix and Konami, have decided to suspend their online gaming to help conserve power.
Square Enix has suspended use of Final Fantasy XI and Final Fantasy XIV for a week that began the 13th of March. They have announced that the April Final Fantasy XI service charge for April will be waved.
Konami has suspended its Metal Gear Online as of March 12th with no date announced as to when it will return.