Not just Mecca, if you use 50% you can take out every major Muslim city in the world :D
that’s the beauty, if used 50% in just one place at the same time, there would be nothing left but a giant crater where their moon rock used to be, the whole muslim world would be disillusioned (everything is allahs will). The rest of the cities would burn themselves down without us having to feel guilty about killing anyone.