ALBUQUERQUE, N.M. (WHAT THE TECH?) —  You may have seen social media posts about thieves breaking into cars by copying key fobs. It’s a real problem.

It’s called a relay attack and here’s how it works. One bad guy is next to the car and another crook follows you, getting close even inside a store. Then the bad guy next to you has the device that clones your key fob and sends the signal back to the crook standing by your car. And then he unlocks it.

Your key fob emits an RFID signal which unlocks the car. By cloning it, the device makes the car’s anti-theft system think your key fob is next to it. No broken glass, no alarm. 

Just like you’d do when you return, the thief simply unlocks the car to steal whatever he wants, or even steals the vehicle.

Here’s the tricky part. If you lock some cars by using the inside door lock, it prevents the fob from sending a signal. Other cars might turn off the key fob if you lock the door with a key. You should try on your own vehicle.

If that doesn’t work, you can keep your key in something called a Faraday pouch or purse. I couldn’t find one in my local Walmart store, but they are available at most online retailers. These pouches block the RFID signal. You’ll just have to take it out to lock and unlock your vehicle.

If you’re very concerned about this, you could also disable the key fob by removing the battery.

The RFID cloning devices aren’t available in just any electronics store, but bad guys buy them online on the black or gray markets. So be aware of what’s going on around you.