It's pretty ridiculous to consider the operation of copying the data from HDD to RAM to fall under the jurisdiction of copyright, but it does in the US.
http://en.wikipedia.org/wiki/MAI_Sys..._Computer,_Inc.
That means if you violate the EULA, you forfeit your right to make a copy of the program, which means you are no longer permitted to make copies of the program into RAM (ie run the game) unless you are the *owner* of the software (and as a licensee you do not "own" the software), and therefore by doing so you are infringing copyright. Thus, by inducing you to violate the EULA, bot makers/sellers are not only interfering with the end-user's license with Blizzard, but also inducing them to commit copyright infringement.
It's a dubious legal theory but high-priced lawyers will win it nevertheless.
Realistically, congress needs to amend 17 U.S.C. § 117 to allow software *licensees* to make copies necessary for utilization of computer programs.
e: oh, weird. Just found the glider case:
http://en.wikipedia.org/wiki/MDY_Ind...rtainment,_Inc.
Apparently the appeal was partially successful, as it was found that "for a licensee's violation of a contract to constitute copyright infringement, there must be a nexus between the condition and the licensor's exclusive rights of copyright. Here, WoW players do not commit copyright infringement by using Glider in violation of the [terms of use]".
However, at least one judgment survived the appeal -- the DMCA anti-trafficking clause. Not sure the specifics of that one.