Breaking into a home is so blatantly easy I doubt anyone would bother with the lock even if they had the key.
Truthfully I don't even lock my house. Once someone has decided to enter unlawfully they are going to do so regardless of your locks.
Of course my dog will eat them so its not a huge concern for me.
Fences, locks and lights are all non deterents, these items just ease people's minds and give a false sense of security.