Check out this mouse jiggler that jiggles your mouse annoying when plugged into any computer. You might have to call the IT department if you don’t know if the USB jiggler was inserted into your PC by your evil spirited co-worker. Talking about evil spirited co-workers, check out the USB Mouse Prank Garrett did on me the other day. (Well, Garrett is not evil, he’s a nice guy~)
Why? Either to make sure your screen saver doesn’t come on, or as a practical joke (depending on which mode you select). It was originally marketed towards security professionals and forensics experts who needed to ensure a laptop wouldn’t go into a password-protected screen saver mode while they were away.