Drivers in Austin, Texas thought their cars were possessed when their horns started honking in the middle of the night or their vehicles simply wouldn't start.
But it seems the culprit was a hacker exploiting a system used by auto dealers to immobilise the vehicles of people behind with their payments.
Police yesterday arrested 20-year-old Omar Ramos-Lopez, who was laid off from Texas Auto Center in February.
"We initially dismissed it as mechanical failure," Texas Auto Center manager Martin Garcia told Wired.
"We started having a rash of up to a hundred customers at one time complaining. Some customers complained of the horns going off in the middle of the night. The only option they had was to remove the battery."
The immobilisation system, from a company called PayTeck, http://www.payteck.cc/ is installed by many dealers as an alternative to repossession. It can be used to disable the car's ignition or start the horn.
Ramos-Lopez allegedly used a former colleague's login to activate the system, first picking out specific customers and then starting to work his way through the entire database alphabetically. More than 100 owners were affected.
According to Associated Press, the havoc didn't end there. The hacker also had some fun changing customer names, with staff surprised to find that dead rapper Tupac Shakur had apparently recently bought a car.