One report said that in a shopping car park, a person locked their car only to hear it unlock again. The person then locked it again only to hear it unlock once again. The person then turned to see two men looking at the car suspiciously. The owner had no doubt the men had something to do with the weird situation.
If such capabilities are possible, it would allow thieves to enter and exit a car without the owner knowing they've been robbed. Well, it won't be as obvious that the car has been broken into since nothing is 'broken' in the first place.
The technology behind this has been circulated in an email in the US, warning collegues and friends of what is possible. It basically explained that once a car is locked using the keyless entry device, a code is sent to the car. This code can then, apparently, be picked up by the tech-minded thieves using a special tool. This tool then resends the code to the car, thus unlocking the doors.
We haven't heard of such devices reaching Australia yet (although it's going to be hard tell), but the American police advise one way around this is to lock you car via the hand-held key. This method doesn't send off a signal that thieves can pick up.
Police also warned motorists against leaving valuables in their cars.