Destiny 2 is experiencing a server connection error on PS4 at the moment. Players are unable to login, with a message about online multiplayer permission and profile sign ins.
Bungie is aware of the issue, tweeting out that it's being investigated:
We are investigating players on PlayStation 4 receiving errors indicating permissions to access online multiplayer may have changed.September 7, 2017
But before you get all angry at them, it might not be entirely the studio's fault, with PlayStation also looking into an issue with the network overall:
We are aware that some PS4 users have reported issues accessing PSN tonight. Thanks for your patience as we investigate.September 7, 2017
At the moment there's not a lot anyone can do except wait (the PlayStation helpline is promising a resolution within 24hrs). Some other online games are experiencing minor issues, but Destiny 2 seems the worst affected - not surprising considering it's probably got the most people trying to access it right now.