Blizzard announced on their forum that they're suing one of the heavily spamming World of Warcraft gold sellers:
As many of you know, the latest content patch, along with many great new content additions, contains technical counter-measures designed to combat in-game gold spamming. Our efforts to reduce in-game abuse and create a fun, safe environment for everyone are never-ending.
With that said, we felt that it was important to share with the community just how serious we are in our efforts to combat this type of abuse. Blizzard has filed a federal lawsuit against the operators of Peons4hire, a popular gold-selling organization which many of you have no doubt seen advertised. As part of the lawsuit, the operators of Peons4hire have been asked to immediately cease all in-game spamming efforts by all entities and websites under their control.
If this organization refuses to act accordingly, further legal action will be taken.