Stuxnet and Fanny were USB Trojans with malicious intent.
This was intended to show the USB current limiters, TVS and transorbs do not protect against steady -100 to -200V at a few Watts or many kJ. Eventually, something will fail. Hardware, ethics or humanity. But probably just an SMT fuse.
this was intended to be a proof of security breach and not for malicious intent.
Lesson learned … before inserting an USB device into your PC, be sure about its origin.