The university of texas used to teach a psychology class that spent some time on "the criminal mind" regarding things like this.

One of the most interesting bits out of this was the "barrier effect" and cul de sacs.

If your house is at the end of a cul de sac, it's more often broken into than any other house on the block. All the other houses are just houses. Yours is where they have to turn around while driving, they spend more time looking at it and really notice it.

The barrier effect is a means of protecting your house psychologically. Any barrier between your house and the street, no matter how tall, can provide a mental barrier to the crook. A small bush that circles the front of your house. A short fence, a little rock wall. It doesn't matter if the barrier can be scaled with ease. It's a projection of the thought that "this property behind this line is mine." Houses that had some barrier in front were less likely to be robbed.

Greg