Japan-hosted multiplayer servers are being shut down to conserve power in the wake of the earthquake and associated nuclear power plant damage.
Square Enix confirmed the temporary closure of Final Fantasy XI and Final Fantasy XIV servers, as well as PlayOnline services, via a post on the PlayOnline news portal, The Lodestone.
"Due to the continuous earthquakes occurring in the eastern regions of Japan since March 11 2011, the power companies in Japan have encouraged everyone to cooperate by conserving as much energy as possible as it is feared there will not be enough power supply," the post explains, before noting that players will not be charged any subscription costs during April.
The Kojima Pro Live Twitter feed confirmed that Metal Gear Online would also go dark.
"To conserve power we are temporarily stopping the MGO servers. Timing for the recommencement is TBD. Sorry for the inconvenience."