Here's an article from yesterday's NY Times that relates to the whole doormat situation. The article quotes Francis X. Gribbon, the deputy commissioner for public information for the FDNY.
The building code, Mr. Gribbon said, “includes language that says, ‘Corridors shall be kept readily accessible at all times, free of combustible items.’ ”
Are doormats combustible items? Well, yes. But this still sounds like ball-breaking to me.