[Updated] PSA: PlayStation Network Currently Experiencing Connection Issues And Sony Is Aware
Update: Sony is aware of the issue and looking into a solution.
PSN update: we are aware of the issues some users are experiencing, and are working to address them. We'll keep you updated.— PlayStation (@PlayStation) December 8, 2014
The PlayStation Network is currently experiencing connection issues and showing an "undergoing maintenance" message when you try to sign online.
The PlayStation Network status page currently shows the network as being online, but mine and news editor Mike Futter's attempts to sign online have returned errors.
A group has claimed responsibility for this and the recent Xbox Live downtime, though a connection between the group and the downtime has not been confirmed.
We've reached out to Sony for an update and will update this story if and when we get a response.