How can you know that the first part of this sentence is true without knowing the answer to the second part?
Possibly I've never seen a sentence like this. . . and it doesn't seem to be in this list http://en.wikipedia.org/wiki/List_of_fallacies
It's sort of like saying "Dogs have black collars" and then asking others which dogs have black collars.
Definitely, I will learn something from this thread.