The National Insurance Crime Bureau, which is a fraud prevention unit paid for by insurance companies, is warning car owners that break-ins by thieves using a mystery device to unlock keyless car doors by mimicking their key fobs are becoming more common.

Reports of the break-ins started coming in slowly over the past two years, but law enforcement is stumped as to how it's being done, since the ways researchers have figured out to do it involve either complicated surveillance or equipment that's too large to lug around, unlike the small boxes that are being used.

The good news is only things from inside the car are being stolen, not the car itself, since the key fobs for starting a vehicle have not been shown to be vulnerable to hacking so far.

CHECK IT OUT: A thief using themystery device last year in Long Beach, California, to break into a car:


Video from the Long Beach Police Dept. showing a thief using a wireless device to break into a vehicle.