[UPDATED] According to Sony and the PlayStation Network status page, PSN is now back up and running. You may need to re-boot your console for it to pick up the availability if you can’t connect straight away.
Sony is having a rough time of it recently as the PlayStation Network is suffering outages once again, Sony suffered similar problems on the 26th June which were caused by external factors.
The PlayStation Network appears to be unresponsive for players in Europe and North America with players around the world taking to Reddit and Twitter to vent their anger at being unable to play. This is especially an issue for players in North America who generally have today off as part of the 4th July Independence Day celebrations.
According to the PlayStation Network status page both PlayStation 3 and PlayStation 4 are affected.
We’re aware that PSN is experiencing connectivity issues. Thank you for your patience as we investigate. http://t.co/0H0knwwmPY
— Ask PlayStation (@AskPlayStation) July 3, 2015