No security system is foolproof, whether electronic or mechanical. Given enough time and determination a thief can make off with your vehicle. However, most thieves will look for a car that is easy to steal and steering locks are a good deterrent as well as providing a significant obstacle. If you are concerned about vehicle security we would always suggest using more than one device - a steering lock, Faraday pouch and an immobiliser would stop many thieves from stealing your car.