Did you hear about that owl that was removed from a libary in Georgia?

But what's the joke? That there was an owl in the library? That the owl used only the subjective "who" instead of the objective "whom"? Since the word "who" was not used in a sentence, it was neither correct or incorrect. The same can be said for the word "whom". 

Oh, now I get it. I have no sense of humor. That must be it!