One of those dead birds was found on the birthday of the hero of roadkill photography (and more), Jack Adams. Definitely one of the coolest people I've never met.
Also I dont think you have to go vegan. Personally I would never do it because I quite like cheese and pancakes. But I am wondering a bit about the thoughts behind this protest grafitti. Would it be like: "look at how happy those cows would look if they were just hanging around in the grass. Lets not eat them!" Or maybe like: "Do you think this plastic, square cow looks tasty? This is how all cows look, because they are so modified. So you should go vegan." Or maybe somebody was just a bit high (it is amsterdam after all) and sat on the cows and then fell off because they lost their balance, but then they got very pissed off at the cow for no reason at all, and then wrote "go vegan". And I hear you think that that wouldnt make sense, because if you are pissed off at the cow, you want it killed. But it is more that if we would all go vegan, there would be a lot less cows probably. Eitherway. For whatever the reason may be, I'm glad they did it, because it makes me smile.