A sort of behaviour of antivirus when you connect stick: scan first, and then you get to connect..
If you put a uC on it you could actually try to mount USB and check if it is in fact a functional USB device...
So... all I need to do is add a small microcontroller to my USB kill stick and I can bypass all your defenses. It can pretend to be a real USB device for five seconds before zapping you. Five seconds would give the capacitors time to charge nicely.
Like I said, it is like with viruses, you can't stop the back and forth game... Likewise, if you make a surge protector, i can always make a stick with more energy and burn trough...
But unlike viruses, that can come unnoticed, somebody has to hand you this crap, and you have to willingly put it in USB port for some reason...
And while now they are claiming some "testing bullshit" as a reason to sell and own this, if you did all that you said (and possibly more..) to SURPASS protection schemes, than by making and owning one of those you are proving malevolent and deliberately designing, making and using a device to do deliberate destruction...... And that is clearly illegal..
Some time ago there was a scam, where a pretty girl with a t-shirt with a logo of a well know company was giving away USB sticks, also with a logo of that company..
Like a normal marketing campaign.. Except USB sticks had zero-day root kit on it to spy on your PC (and to make it more fun, it wasn't only M*soft target on it)..
So you take it (it was free, right?) put it in a pocket... One of these days you need a stick, and use it...
They might have as well given you one of these USB killers...
Morale of the story: Like you mother told you , don't take candies from a stranger ........
As I sad before, it doesn't bother me personally, I see no scenario that I would stick a thing like that in my PC without knowing who was to blame... In that case they would pay for the damage... Case closed.
In a public, unattended use, whatever you want to damage, just slam it with a hammer.... No need for USB bull***t...