What's your first instance of a infinite loop which ended badly?

Mine was a loop to calculate prime numbers.

My computer came to a halt within 5 seconds :S

I was learning HashMaps for the first time and messed up something that resulted in my computer ramping the CPU up and hearing so much I threw it off my lap and it died all within 10 or so seconds. Long enough for me to watch it unfold and marvel in my failure, haha.

I guess it was when I tried to write some simple gameloop.. I ended up using xna/monogame

I typed Google into Google

Loaded a nodejs console on another person's computer. Made a hello world program to run until halted as a demo. TeamViewer goes offline and I get a phone pic of a BSOD on hangouts. I learned JS in a web browser where that won't crash the computer, but I felt ashamed.