This is a neat way to try and keep a weapon from falling into the wrong hands. This smart handgun made by Armatix uses a frequency controlled safety to disarm the weapon when it is not in range of the transmitter. The transmitter in this case is a watch worn by the user. When the watch is in range of the weapon a green LED lights up on the back. If anyone should try to pull the trigger on the device while not wearing the watch the gun will not fire and a red LED will light up. This could be especially useful for law enforcement since it would prevent anyone from taking their weapons and using them against them. It could however prove to be unreliable in critical situations which would spell this handguns doom. Time will tell if this idea is practical enough to implement widespread usage, but what do you think?

References

1. dvice.com