Peculiar sign of the day

On Monday, I saw this sign on the front door of a mosque in Tooting in south London.



Does this mean that leaving torn copies of the New Testament, the Torah or the Book of Mormon on the steps of the mosque is okay?

(Sorry about the slightly blurred photo. I didn't want anyone to ask me questions about why I was photographing the mosque, so I only took one very quick photo as inconspicuously as possible).