I have been longing to photograph this ever since I saw it for the first time! So yesterday my camera and my body were in the same location. Of course it makes me smile and I know this is not a deliberate deterrent to potential worshippers! However, it is a subtle deterrent in that it illustrates how we often think as regular churchy peeps - how much more sensitive would it be to have a sign that says 'Stay safe, please use the next entrance' or similar. And I think this is more of a rural, traditional chuch phenomena.
A good article in the Guardian by Theo Hobson expanding this here
Lots more to say about this... soon!