The ID is banned, to those that can sign in and out, once you turn off your PS3, you will lose access to PSN, you will not be able to log in again. This same thing happened to my cousin the other day. I got banned from the ID and he didn't. He could sign in and out just fine and I couldn't sign in once I signed out. Once he turned the console off, he could no longer access the ID either.
(I'm one of the lucky few that still has access on PSN as well right now, I plan to keep the PS3 on all night if need be lol)