Blizzard certainly doesn’t seem to care. Especially since it’s been proven by the indie teams running private realms that botters can be eradicated.
That being said, at least once a day I’ll do a /who in those dungeons and report all of the people with those classes/levels if they have a gibberish name, or a name that was obviously made using the game’s random name feature. At the moment, I have 4 pages of “Thanks for reporting” mail from Blizzard in my character’s inbox. It’s clearly doing nothing to stop the problem, but I at least like the idea that I’m helping to waste the money of the people who do it.