After years of KFC boycotts, PETA will once again picket McDonald's in a bid to trigger a change in the way chickens are slaughtered in the US. American farms usually shock chickens before beheading them, a method the animal rights group calls inhumane. PETA prefers the European method, which involves gassing animals, reports the Chicago Tribune. McDonald's studies say neither method is better. US farms would have to shell out big bucks to shift to gas technology.