Indestructible, yes -- immovable, no

It's the early 1970s, and student unrest is roiling this big state university campus. "There were numerous demonstrations," says a pilot fish working there. And since our computer room was on the ground floor of the main building where students demonstrated, our administrators decided to beef up security."

First step is to replace all the glass windows with Lexan, a nearly indestructible plastic. That includes the large pane of glass in the door leading into the computer room.

"After this was replaced with Lexan, I asked the computer room supervisor if he thought everything was secure," fish says. "He proceeded to show me how secure the door was by throwing a claw hammer at the window in the door.

"The Lexan didn't break and the hammer bounced back at us.

"However, the Lexan did pop out onto the floor.

"We called the facilities people back to install additional barriers."