Dammit, I can't remember the name and when. A quick skim through BBB and MitS didn't yield anything but I could have missed it.
Any ideas from the ever-helpful board?

Are you thinking of TerraFirst! ? Only that one's been that way almost from the beginning.

Ah. My money was on Greenwar.
Tnx for the quick and safe delivery!

IIRC - always a caveat when I don't have my books with me. I could be wrong in this.

Edit:
Found this much of confirmation at least in "No Man's Land" (2057): the March Hare was a toxic shaman from Greenwar who had declared war on the yakuza.

Well, I think this was mentioned either in the Underworld-SB or some weird book like Cyberpirates or Target: Smuggler Havens, but it was actually Greenwar which basically broke down after being massivly infiltrated by toxic shamans and losing much of its popular support.

TerraFirst had it's (rumored) toxic shamans right from the beginning and is still alive and kickin'.