Actually, animal welfare groups have been successful in improving the treatment of animals intended for slaughter. I don't know that it was PETA (actually, I think it wasn't) but the animal protection folks did target McDonalds in order to get the largest buyer of groung beef to require their suppliers to treat their supply in a more humane way. It worked - McDonalds does indeed require suppliers to subscribe to certain humane slaughter methods. Unfortunately for PETA, I don't think they will achieve the same level of success due to their tactics. But PETA's confrontational tactics will attract additional animal right activists to PETA - which is most likely their real objective.

KFC, I read, already complies with some fairly stiff standards. To meet PETA's standards, I suspect they'd have to replace everything on the menu with cellulose derivatives.