That someone with access to the the database itself messed (not hacked) with it.
It's clearly connected to the database because the vBulletin icon is being displayed. So, the error is within the vBulletin software, otherwise it wouldn't be showing that message at all. They'd be getting an HTML error instead.
I conclude that someone without knowledge of web did something they shouldn't have. If the Ron Paul Forums are smart they will have backed up the files and database.