In university we were taught C programming. We started with simple things like loops and stuff. After a while the topic processes, threads & stuff came up and of course we were instructed to use that.
In the computer lab there where only thin clients so everything actually ran on the server.
A good friend of mine - not know what was about to happen - entered:
while (true) {
fork();
}
Astoundingly it took a whole minute until the server froze. π€£
That was the same server most of the school stuff ran on. So nearly everything went down. π
He got scolded by the sysadmin the next day but nothing serious happened.