Just make the neighbor's condenser look more appealing. Both neighbor's at a previous house had theirs swiped a couple times, but not ours. I like to attribute that to the holly bushes I planted around them.
On the construction side, every project I've been involved with over the past decade or so has had some type of theft incident. I've started including 24-7 security or video surveillance as a requirement in all of our architectural specifications just so i can't get pinned for the the cost of the damage it causes when they rip the walls up. What's nuts is that often times the thieves look right at the cameras and smile...and still don't get caught.