Earlier quoted context omitted.
Point a webcam at the screen and wire a mouse to the computer controlling the webcam, you'd have to simulate the computer moving the mouse like a human would but I don't see why it wouldn't work.
You've now forced spammers to purchase webcams. And write code or whatever to make realistic mouse movements. This is expensive. Whatever they're doing likely isn't worth it anymore.
I can see it being possible - racks of "robot arms" that move mice based on whatever criteria is needed (in this case, reCaptcha).
It works for 3D printing, as well as device testing - so in theory, this could be done too...