Humm, those a toughies, in so far as how one draws up their own ethical paramaters. IE should human ethics apply to animals, or should animals have rights to begin with etc.
Though evolution also made us into the dominant specis of the planet via our omnivourous capacity. With out the eating of cooked meat we wouldnt have developed the higher levels of intellegence we currently pocess today as a species.
Additionally, it looks as if everything living, feeds off something else that is living to sustain itself in a similar manner.
The animals are still being killed, so I assume from their point of view they would rather not, everything living after all as a natural drive to survive. From that perspective I dont think the animals give a flip wether they get stunned first or not, they just want to live period. If peta really wants to go after something evil being done to animals, they should perhaps be more focused on the industrialization methods used in chicken factories and pig farms where conditions are abhorant from beinging to end for the animals.
Is it a veiled attack against certian religions and cultures? I suppose it could be viewed as such, depending upon just what the real motivations of the group behind it are.