Drivers were locked out of cars when keyless entry failed in Las Vegas: This is an odd one, and it appears to be an interference problem. Something, somehow, flooded the keyless entry radio frequencies for many vehicles on one day with junk interference. Portents of things to come as we rely on extremely low-power short-range wireless technology? Or a fluke? It might be the military (accidentally).
You can also read a semi-related story about how this writer's car was stolen even though it uses a resistance-based encryption locking system. He's asking for suggestions about how his car was ripped off, but it's obvious to me that he offers the solution in his article: an inside job at the dealer or social engineering to get a duplicate.