Stupid Mac Tricks Book, Replacing Startup Screen

During 12th grade, I read up a book called "Stupid Mac Tricks." One of the tricks in it was how to replace the Mac's startup screen. As a joke, I made a graphic of a black-bordered white box with a gray background. The text in the box read, "This computer will self-destruct in ten seconds. Thank you, Apple Computer Co."

I made this the startup screen for a computer in my high school's computer lab.

The next day an "out of order" sign was taped to the monitor. The lab attendants usually wrote the reason on the bottom edge of the paper, so I leaned in to read what had been written there. It said, "Will self-destruct."