I was just wondering, reading around, what is the difference between a user that is banned and a user that is BANNED?
The use of all upper case, mainly.
The difference is the same as “Get out” and “Get the f*** out”. 
Strangely enough, I suspect that Q.E.D. is about 85% right. On the Mighty Admin. Board available only to the few, the proud, the Admins., there are a number of useful bits of information about you and me and every member. Some of them are changeable. One of them grants him/her access to posting on the board, running searches, and all the other privileges of being a Doper, and can be toggled to “This turkey can do nothing except read the board powerlessly” and another one governs what is shown below your username as your status. SDMB, being “stripped” of the sorts of bells and whistles that smaller, less active boards can support, has only four categories, IIRC – Member, Moderator, Administrator, and Perfect Master (the last being an attribute of only the omniscient Cecil). But it can be modified at will by an Admin. – I recall one banned member whose status was “Too Stupid for Words.”
So rock bottom, it depends on whether the Admin. in question who is logging in the banning has the attitude “It’s too bad about this guy; he had promise, but he just refused to follow the rules” (and types in “Banned”) or “Good riddance, and may the fleas of a thousand camels infest your armpits just after you’re placed in a full body cast, Turkey!” (in which case he or she types in “BANNED” in all caps).