Back before the sophisticated car security systems, the "devices" often used to steal cars had the incredible hidden abilities to also hang clothes safely off the floor or drive nails into innocent sheets of plywood. Modern car thieves have been spotted new generation of devices that seem to be able to unlock many cars instantly by simply being held against the vehicle.
Long Beach police are so far baffled by the devices, which appear to operate by being held against the targeted car. In the video associated with ABC's story, the thieves break into two Acuras, and unsuccessfully attempt to open a Ford Escape and a Cadillac. According to police, a wide variety of makes have been victims.
Based on what's happening, I think we can do some speculating. I think it's safe to say the device is an RF transmitter operating in the 300-400 Mhz range, and using a brute-force method to send the remote-entry codes to the car. I'm guessing the reason for the direct contact with the car is because the device has a very low-power transmitter to keep other non-targeted cars from being triggered. I'm talking a bit ex recto here, but this seems a plausible guess.
I'm pretty attuned to car theft lately, so be careful, people.