I had a great cron prank that I pulled on the only other linux user at my high school 2 years ago. It made a folder, took a screenshot of his background, moved

I had a great cron prank that I pulled on the only other linux user at my high school 2 years ago. It made a folder, took a screenshot of his background, moved all of his desktop into said folder, then changed the background to the screenshot. In retrospect, It was probably overkill, but at least he learned to use ctrl+alt+l when sharing a lunch period with another linux enthusiast.