The group that was able to hack a Tesla reported its findings to the electric car automaker, so this security breach will hopefully be fixed in short order. The event was welcomed by Tesla, which said it "[supported] the idea of providing an environment in which responsible security researchers can help identify potential vulnerabilities."
Last year, potential security pitfalls of high-tech electric and hybrid cars came to light when the US Defense Department's Defense Advanced Research Projects Agency (better known as DARPA) successfully hacked into hybrids from Ford and Toyota. Questions about the security of the Tesla Model S have been raised before. If you're wondering why all this might be such a big deal, we suggest you watch this.