Jumpstart
Wow. Exposing electrical contacts to the outside world is a very clever idea.
I wonder what would happen if somebody applied high voltage to those contacts. Sufficiently high to blast the electronics to buggery. Which way would it fail? One would hope it would fail locked, otherwise burglars have an easy way in. OTOH, that would allow a DoS attack on your lock (but no worse than superglue in a conventional lock).
Except I doubt you can guarantee which way it's going to fail, unless Nest put a lot of effort into ensuring it fails locked in those circumstances. And even the best design might behave unpredictably if you used one of these bad boys on it.
Note that the above device is intended purely for high school science experiments and not for constructing a contact electroshock weapon (like a TASER, but without the dart-firing capability). It would be illegal to use one of these to construct an electroshock weapon. So it's a good thing people can't buy them dirt-cheap on eBay. Ob Big Clive video (contains one of those devices, alcohol, technical stupidity, profanity and electric shock).
Biting the hand that feeds IT
