Recently Tesla car theft became a hot topic, since the keyless entry system is vulnerable for the so called relay hack. Tesla came with a fix, although it's not the best solution ever.
More or less every car that uses keyless entry is vulnerable to relay hacks. Car thieves position a device that can pickup the very weak signal near your keyfob and transmit it to a device near the car that outputs the same signal, thus tricking the car in thinking the key is nearby.
This resulted in a streak of Tesla thefts in The Netherlands and Sweden. The only solution was to put your keyfob in a cover that would block the signal, and only taking it out when needed. Far from ideal.
Now during the past month, Tesla pushed a firmware udpate to the Model S (Model X to follow) that gives owners the option to turn passive entry off entirely. When turned off, the car only unlocks after a double press on the keyfob. This makes the relay hack impossible, since the car won't respond to the passive entry signal anymore.
The new setting can be found under Settings > Doors & Locks.
Although this of course prevents the car being stolen, I wouldn't call it an actual fix. The keyless entry isn't fixed, but disabled. I certainly hope Tesla will find a way to make the actual keyless entry safe to use in the future.