I locked my car. As I walked away I heard my car door unlock. I went back and locked my car again "three times". Each time, as soon as I started to walk away, I would hear it unlock again! Naturally alarmed, I looked around and there were two guys sitting in a car in the fire lane next to the store. They were obviously watching me intently, and there was no doubt they were somehow involved in this very weird situation. I quickly chucked the errand I was on, jumped in my car and sped away. I went straight to the police station, told them what had happened, and found out I was part of a new, and very successful, scheme being used to gain entry into cars.
Two weeks later, my friend's son had a similar happening....While traveling, my friend's son stopped at a roadside rest to use the bathroom. When he came out to his car less than 4-5 minutes later, someone had gotten into his car and stolen his cell phone, laptop computer, GPS navigator, briefcase.....you name it He called the police and since there were no signs of his car being broken into, the police told him he had been a victim of the latest robbery tactic -- there is a device that robbers are using now to clone your security code when you lock your doors on your car using your key-chain locking device.
They sit a distance away and watch for their next victim. They know you are going inside of the store, restaurant, or bathroom and that they now have a few minutes to steal and run. The police officer said to manually lock your car door-by hitting the lock button inside the car -- that way if there is someone sitting in a parking lot watching for their next victim, it will not be you. When you hit the lock button on your car upon exiting, it does not send the security code, but if you walk away and use the door lock on your key chain, it sends the code through the airwaves where it can be instantly stolen.
Snopes notes (http://www.snopes.com/autos/techno/lockcode.asp): Research to be presented at the Network and Distributed System Security Symposium in February 2011 in San Diego will demonstrate a system whereby with the use of two antennas and other specialized equipment (costing between $100 and $1,000), vehicles can be tricked into opening. However, that system requires that one antenna be within eight meters of the key and the other located very close to the vehicle. It is expected car manufacturers will devise ways to circumvent the new methodology.
Many different law enforcement agencies have observed that the overwhelming majority of automobile break-in thefts (i.e., the stealing of property from car trunks or passenger compartments) are crimes of opportunity perpetrated by people in search of items they can quickly and easily re-sell for cash. Such criminals are not wont to delay their gratification for hours or days while their code grabbers crunch numbers and work out how to keylessly open particular cars: They instead resort to quick, tried-and-true methods such as jimmying locks and smashing windows, and if they can't get into a given car easily, they'll simply move on to the next one. None of the police agencies we spoke with had ever heard of an instance of an automobile break-in theft being accomplished through the method described above.