Yes, all members are assigned to a group.
Users start in a group called Newbies (which limits posts to one every 5 minutes).
This helps weed out the spammers who tend to create multiple junk posts in a matter of minutes.
After we've determined they are most likely legit they are manually moved to User group.
There should be over 92,000 Users, it now shows 77,627 assigned to User of the 92650 total.
It's like the Newbies that were moved over suddenly fell out of the User group.