Actually, that someone was a Chinese company that helped organize the event in the first place.
A few days ago we wrote about a conference that was about to be held in Beijing where participants were encouraged to try and hack a Tesla Model S. Those who wanted to try were provided with a PC and a Model S, and the goal was to try and successfully control the car from the PC or make the in-dash browser visit "specified websites, presumblambly to see whether the malware infection could be possible." If anyone managed to do this, they'd win $10,000.
Tesla didn't sponsor the conference, and only requested that the hopeful hackers "act responsibly and in good faith." Apparently that's just what happened. A Chinese internet security company called Qihoo, who just so happens to be one of the organizers of the conference, has reportedly managed to hack the Model S by remotely controlling the horn, door, locks, headlights, and moon roof while the car was in motion. How did Qihoo managed to pull this off? It's not giving any details, only telling Tesla owners to be careful while driving in the rain because the moon roof could suddenly open without warning. Tesla, for its part, has announced that it's taking immediate action to fix these vulnerabilities.