Online game servers don't come for free you know. Someone has to look after them, and if no one is playing on them, they get closed. So this is why Sony is closing a few...In an official announcement made in good time for the few remaining online players Sony states that:
"As of 1 October 2012 you will no longer be able to use the online features of the following game:
PlayStation 3MotorStorm Pacific RiftPSPMotorStorm Arctic EdgeSOCOM: Fireteam Bravo 3After this date, you will still be able to play these games offline."
More detail at
Sony