What you do is somehow get to somebody's computer and remove thier mouse ball and hide it. Then after a week the victim will probablt get a new mouse. Then if you have thier old mouse put tape on one of the rollers on the inside, then but the ball back in and replace thier new mouse with the old mouse. then depending on wich roller you taped the cursor will only move up & down or side to side. Again they will probably get a new mouse...
This works best if thier new mouse is the same as the old.