Neverwinter Nights, Microsoft Flight Simulator X, SWAT 4, Hidden and Dangerous 2, and Star Wars: Battlefront, are reporting that the GameSpy-powered multiplayer servers behind those titles and more have been shut off without notice. The GameSpy service was sold to publisher Glu Mobile from IGN a little while ago, so it's that company that's apparently responsible for shutting down these servers.
Another one of the games affected was Sniper Elite, and developer Rebellion says its hands are tied: Glu wants to charge a lot of money to turn the servers back on, and Rebellion doesn't have the resources to transfer the multiplayer on this old title to another service. Rebellion points out that fans of the game did get seven years of service for free. And while GameSpy's matchmaking is down, players of some of these games can still connect up online manually by IP.
Angry players have taken to GameSpy's old Facebook page to register their wrath, but there's no official response just yet.