Read Section 5 of the WOW EULA (End-User License Agreement) and you might be concerned about allowing Blizzard Entertainment to "monitor" your machine for "unauthorized" third party software. Read Section 11 of the WOW EULA and you might be even more concerned because Blizzard seeks to limit its liability to "the total fees paid ... to Blizzard during the six (6) months prior to the time such claim arose". It remains to be seen whether clauses of this nature are in fact enforceable.
The question really is - has Blizzard gone to far in its efforts to prevent cheating? Gary McGraw (CTO of Cigital Inc.) and Greg Hoglund (CEO of HBGary Inc.) seem to think so. In the meantime, in response to the "monitoring" software Blizzard calls "The Warden", McGraw and Hoglund have released their own piece of software they call "The Govenor". Their software "closely monitors The Warden and curtails activities the authors deem invasive".
And so the war between cyber-defence and spyware continues.