ZDNet - Thieves Exploiting Vulnerability in On-Board Diagnostic System to Steal BMWs. Thieves have figured out a way to steal BMWs with keyless entry technology. They are able to bypass alarm systems. It is believed that the thieves are gaining access to the cars' On-Board Diagnostic (OBD) system to program new key fobs. The vehicles' OBD ports are constantly powered, even when the vehicles are off, and they do not require passwords.
Source: http://www.zdnet.com/hackers-steal-keyless-bmw-in-under-3-minutes-video-7000000507/