While it is only a minor thing compared to some of the tragic losses (55 people have died so far in the United States, millions are without power and thousands have had their property severely damaged or destroyed) caused by Hurricane Sandy, Activision community manager Dan Amrich points out on his blog that the storm has affected online functionality for all Guitar Hero games and several Call of Duty titles.
Amrich warned that some players may experience connectivity issues with multiple games until Activision can stabilize power to its New York-based data centers. The games affected include Call of Duty: World at War (all platforms), Call of Duty: Modern Warfare 2 (PlayStation 3), Call of Duty: Black Ops (PlayStation 3, PC, Wii), and Guitar Hero (all titles and platforms) games.
Activision has no ETA on when things will be back to normal. We'll keep you posted.
On a related note, if you want to help out victims of Hurricane Sandy you can make a donation at the American Red Cross right now.