Keyless entry is key to stealing other people's cars for European crime ring

Convenience often comes at a cost.

For the victims of a sprawling European crime ring that relied on a keyless entry system to steal scores of Mercedes-Benz, the cost was the loss of their cars. And, conversely, for the criminals who so easily boosted the cars, the cost may now end up being their freedom.

According to Europol, the European Union's law enforcement body, on July 16 the Polish National Police discovered thousands of chopped car parts — with serial numbers removed — after searching a "former agricultural property" and numerous apartments. Car thieves had been stealing Mercedes-Benz equipped with the KEYLESS-GO system mostly in Germany, moving them to Poland, and dismantling them to sell for parts.

"The Polish criminal network was well-organized and stole high-value cars equipped with KEYLESS GO systems," reads the Europol press release. "The suspects were able to bridge the keyless lock and engine starting system with technical equipment."

Mercedes-Benz touts its KEYLESS-GO system as enabling the following exciting capabilities: "open and lock the vehicle conveniently and start it up quickly — simply by carrying the key," "driver and co-driver's doors can be opened and locked by touching the door handle without the vehicle key having to be touched," and "the engine can be quickly started and stopped by simply pressing the start-stop ignition button."

In other words, the KEYLESS-GO system allows you to unlock, start, and drive away with a car. Pretty handy.

It's not immediately clear what so-called technical equipment the thieves used, however a method of stealing cars called a relay attack has become quite popular over the past few years. Essentially, once an appropriate car with keyless-driving features is spotted, the thief waits until the car owner is home. Then, with the real keys presumably inside the house and the car parked outside, the thief — using relatively simple digital tools — is able to pick up the signal emitted by the real key insidethe house and make the car think the key is present.

And like that, the criminal can open the car, start it up, and drive away.

The criminal network at the center of today's Europol announcement reportedly boosted at least 34 vehicles. Authorities say they also seized drugs and ammunition during the raids.

SEE ALSO: Car heist video reminds Tesla owners that relay attacks are still a thing

Thankfully, there's an easy — and relatively inexpensive — way to prevent relay attacks. All you need to do is, once home, put your keys inside a faraday sleeve (Silent Pocket makes decent ones). That way, thieves will not be able to relay the signal from your wireless key to their device. And, consequently, stealing your car won't be such a breeze.

Heck, it might even take a physical key.