Good old Error 8071053D is back if you try to sign into PlayStation Network from your PlayStation 3. If you try to log in to a PlayStation web site, you get a page tells you the site is down for maintenance. These outages affect North American servers.
Update: A Sony representative tells Kotaku that the maintenance is now over and PSN account holders may log in again.
It doesn't appear to be regularly scheduled, as PSN underwent regular maintenance on May 24, and the weekend after E3 would be kind of a bad time for that. I'm reaching out to Sony Computer Entertainment America representatives for more info on why this is happening and how long it's expected.