By hacking into an Austin-based car dealership’s immobilization technology, used instead of repossessing cars, a disgruntled former employee of Austin-based car dealership Texas Auto Center disabled over 100 cars, sometimes setting their horns honking wildly, as well. The suspect, Oscar Ramos-Lopez, 20, has been arrested and charged with breach of computer security.

The technology in question is a system called Webtech Plus. Operated by Cleveland-based Pay Technologies, car dealers install a small black box under dashboards that responds to remote commands relayed over wireless pager network. While the system will not stop a vehicle that’s being driven, it can disable a car’s ignition system, or trigger the horn.