Oh, but I agree. It IS a crime to slash their tires, and whoever did it should be ready to face the law for it. Actually, I'm in agreement with the OP, essentially saying: "This is wrong, but it does give me a chuckle."
We could put it in another way: You can put yourself that much in the path of harm that you don't merit any pity. For example, suppose you leave your expensive watch on your towel while going for a nice long swim. If the watch is gone when you return, well sure someone is a thief, but you are a damn fool.
I feel the WBC are deliberately trying to piss people off as much as they can, so if they sometimes succeed, well, tough luck.
Hans