Here's a gorgeous little macro ( ) that, when called (or triggered with a hot key, but you probably don't need that trigger) will warn the user to stop moving the mouse. It does so by filling the screen with a huge display warning. It doesn't actually stop the mouse, but it should scare the user enough to stop moving the mouse. Also, coincidentally, it makes it almost impossible for the user to use the mouse because the screen is blacked out.
Also, this is the first time I've ever got to use the new KM action "Pause Until the Mouse Moves." So I'm happy to have done that.
Mouse Warning Macro (v10.0.2)
Mouse Warning.kmmacros (4.5 KB)