This is posted on the Blizzard forums by Eyonix:

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. We’ll be sure to keep you posted on the progress of this topic.

Kudos to Blizzard for taking this seriously. Though I suspect the fact they want to share this is simply to brag about it, which I suppose is reasonable.

As for the act of gold farming and spamming itself, spamming is definitely bad. We all hate unsolicited advertisements, whether in game or anywhere else. But for the gold farming activity itself, I am not sure if it’s illegal or not. If the farmer is crafty enough, as with all eBay sellers, they only sell “effort spent”. I am no lawyer, but “effort spent” really is not the game companies’ property. However, they ARE using the game companies’ product to make money, whether they are selling the virtual properties, or effort spent, really is not an issue. So in the end, I guess it is illegal