After skimming through the wikipedia article on Adbusters I have to say I find them interesting. But I would classify them as a media organization. Regardless of their intentions, they do things that we consider operations of a media organization if it were another company or group.
I also consider PETA as a media organization as they are all about propaganda for their agenda, which is apparently killing animals to save them from us.
That is categorically false. This protest is about as organic as they come.
"Adbusters Media Foundation is a not-for-profit, anti-consumerist, pro-environment organization"
http://en.wikipedia.org/wiki/Adbusters
They concocted the idea, started it, Anonymous did some promotion, and it caught on with people