First of all, vegans are clinically psychotic. It is a delusional SICKNESS to believe it's wrong for us MAMMALS to drink milk on which we thrive at the biochemical level. Want proof? Put a bowl of milk on the floor for a dog or cat (or the family of amazingly tame, friendly raccoons that always hang around outside my house) and just watch how FAST that milk disappears.
One thing PETA lunatics are simply too stupid to understand: if early, protohuman cave men hadn't started eating meat, they never would have gotten the big bursts of proteins and fats that caused our brains to grow and become more and more complex, eventually achieving sentience. Our brains are made of fatty tissue you don't get from plants. Remember the scene in "Hannibal" when everyone's favorite shrink sauteed a slice of Ray Liotta's brain (the "bad manners" part) and fed it to him? In real life, I'm sure it would have tasted delicious.
They're also too stupid to understand that mankind has been eating meat for so long we've made physical adaptations to it; we have sharp, incisor teeth specifically for tearing through meat, our tongues evolved "salty" tastebuds to recognize meat and our stomach acid is powerful enough to have a solvent effect on meat. If humans were designed to eat ONLY plants then the potency of our stomach acid would be the most evolutionary overkill in history! Humans vitally need vitamin B12 and if you're not taking your vitamins like a good boy, then the only way to get it is from animal tissue.