A Russian security researcher going by the name 'Dark Purple' has designed a USB stick that can send 220 Volts when plugged into a USB socket. If this of course happens on a PC or Laptop it will obviously nuke the motherboard, but the same damage will also be done to any other device that has a USB port such as a TV.
The only solution is to remove all USB ports on PCs and Laptops and revert back to using a PS2 Keyboard and Mouse :-)
You can watch the video below
On a separate note, with cloud storage now being so readily available, using USB drives on a network shouldn't be that necessary any more. They generally get corrupted, they get lost, they can contain viruses and all sorts of software nastiness and are just a pain in general. This is especially the case if you work in a school and students are constantly just removing the devices without saving their work first, leading to lost work.