Has the NRU group been on all of the time through this? Did the accounts that posted actually register before that group was activated?
Are there any other ways to register on the site? A homepage or through facebook?
NRU is active all the time. All the spam accounts were registered after NRU was enabled. In the same time period some spam accounts got created and their posts we're awaiting approval, so it is not a consistent behavior.
I can't think of any other way to register account on this board.