Comment by michaelmior

Much less exciting, but when I was in high school I discovered an unsecured messaging service that could be accessed via a Web interface. This included the ability to send messages to any user logged in to any machine. And also the ability to broadcast messages to all machines in the school. I was never bold enough to test this feature but word got around after I showed a few friends and eventually someone decided to broadcast a rather crude message about our principal. One thing this student didn't realize is that all messages are logged and the sender was easily found and disciplined.

It could have been a lot of fun if schools in the early 2000s were as well-connected as they seem to be now. We were still working with overhead projectors at the time.