Your dishonesty knows no bounds.  Read the conversation.  I am responding to someone else's scenario.
If you were really worried about being able to identify everyone publicly we'd be talking about banning hats, sunglasses, etc, etc.

Be honest.  You are making a crappy and easily refuted public safety argument because you don't want to make your real argument, which is that you personally do not like the niqab (as it happens I don't much like it either) and you think that your likes and dislikes should have the force of law.  You are perfectly happy to disregard any consideration of individual rights when the discussion turns to the rights of adherents of a religion other than yours.  People like you are the very reason that documents like the Charter are necessary.