Banned from WOW for using his brain
Aside from the obvious issues as to exactly why one would wish to occupy one's time in such a fashion, this is exactly the sort of reason why I canceled my WOW account some time ago.
Blizzard is failing horribly at managing the natural issues which crop up anytime you enable a network client to run code. This user did nothing wrong, yet from Blizzard's perspective it's "cheating".
The WOW client interface is written in Lua. It's quite possible, and entirely "legal" from their present TOS to modify this code and the accompanying XML to achieve a variety of effects which are not possible in the plain vanila install.
This user gained much less from his actions than others gain from employing so-called "legal" custom clients which expose normally hidden event information such as stun-lock timers and current health/mana for all targets on-screen.
Blizzard needs to tighten their TOS and surveilance software to disallow such mods or open it up so that natural competative market forces will create a more level playing field "literally" for all involved.
The former is quite an undertaking and really is only a stop-gap measure. The server ultimately needs to trust the client and/or limit the client's actions using action-neutral throttling policies. John Carmack who has some measure of expertise in this space, had a few things to say on this quite some time ago. It's a shame Blizzard isn't listening.