I live in tennemant flats, in between back of ours and back of parallel road's flats is a lane. This is the lane the bin lorry goes down as the bin sheds are at the bottom of the gardens.
Very very often people set fire to the bin sheds, they also like to walk along the whole lane without walking on the ground 
ie over all the walls, roofs of sheds etc.
Now the council have put up 6foot metal gates at the end of the lanes. I cannot imagine the type of people who walk over roofs and walls will be put off by a gate?! Surely all this will do it make it more difficult for the fire service to get in.