GMs have already said they have banned well over 20 accounts, and that was almost a week ago. But in all honestly, be it a spam bot or a person doing it for the lulz. You can create an account quickly, and vpns are endless. and be back on within 5 minutes. Shame you can just ignore blocks of the message like other games, that way name doesn't matter.
Best way to ignore is go to
http://www.r99pvp.net/ooc.php copy name, type in game /ignore ctrl v(to paste) if nothing happens, you need to go into key bindings, and bind paste to ctrl v. Then you have 0 hassle of trying to spell name, its quicker then opening your log file.
I would guess its a bot, maybe player making accounts/chars and bot loop msg dunno. Staff could always make it so level 1s cannot ooc at ALL, unless they have X amount of time played(like 1-2 days minimum) if not longer, that way low lvl bankers can still auction items and such.