UPDATE: Panic over, normal service seems to have returned.
ORIGINAL STORY: PlayStation Network is currently out of action, Sony has confirmed.
It's not saying what the cause of the problem is but it doesn't sound like it's a planned outage.
An post on PlayStation Europe's Twitter feed just announced: "PlayStation Network engineers are working hard on restoring the service. However, we have no news on when it will be back online."
We'll update when more details come in. Stay calm...