Eh...that really depends on your definition of public (not that they would have any means of knowing the select groups you have opened it to). I haven't read the WoW TOS in some time, I just thought I remembered you mentioning something about violating it. Meh.
The only groups I've opened it to would be x86 (privately) and one person from my old Bnet clan, AoA. That's pretty much not public.
It also has to do with what you would define "anti-circumvention technology." While it's clear I'm not distributing content from their game that would violate copyright law, what's unclear is whether I'm copying their intellectual property. The anti-circumvention technology that I am circumventing isn't really guarding their intellectual property, though - it's not really even guarding anything. It's really just obfuscation - they encrypt the protocol headers to make it more difficult to understand the messages.
The WoW TOS clearly states that protocol emulation is not allowed, but they can't criminally charge me for breaking their TOS. My liability is limited to the civil complaints listed in the EULA/TOS, which include specifically their right to terminate.
*shrug*
Why not mention JinxBot? It's not like you use the Bot for anything malicious. You simply did it to extend your knowledge on the protocol. I think it'd impress them.
I've never seen Blizzard be anything but nazis for something like that.