I got in trouble once in high school just for discovering and then using `net send` to send a message to my friend that said "Hi from lab 3".
Computer lab access revoked for 6 weeks. Jokes on them, now I send socket messages to my friend that says "Hi from Chicago" and there's nothing they can do about it.
My friend however keeps begging me to use this thing called 'email' because he claims he doesn't see the socket messages.