The Activation Lock feature is included in ''Find My iPhone'' and prevents anyone from using your device should it be lost or stolen. The feature is enable once you turn on the Find My iPhone feature on your iPad, iPhone or iPod Touch. The thief will have to enter your Apple ID and Password to reactivate or turn off the feature on your device. The number of iPhone and iPad thefts have reduce drastically after Apple introduced the feature.
Reverse is the case when it comes to the new Apple Watch, as it doesn't come equipped with the feature. If you lost your Apple Watch or is stolen, just forget about it or pray that person has some sympathy left in them. That's because it is very easy to reprogram the smart watch since it lacks the security feature. This video shows how a thief could steal your Apple Watch and reset it to use it as their own
I'm still wondering why Apple haven't made the feature available on the Apple Watch considering how expensive it is. It Seems Apple doesn't care anymore.