Something you say when the FBI or the police are at your door, and they are after your LUNIX.
Casual use can be caused by a combination of displeasement and fear for Microsoft lawsuits against open source operating systems, such as Redhate Lunix. It may include other, less important things.
When something bad has happened or is about to happen, you shout OH NOOOOESSS as a replacement to the dull, tired "oh no". Extra o's and e's can be added for extra emphasis.
You remember lemmings? When you nuke a lemming he says "oh no" and explodes. If you truly mess up a level beyond repair and the only thing you can do is lose, you mass nuke your lemmings. They all say "oh no".
Variant of "Oh no!", used sarcastically to indicate that what is being referred to is NOT, in fact, something to be alarmed about.
"My World of Warcraft server's economy is ruined! I can now only sell Arcane Crystals for 7 gold coins apiece, whereas before I could sell them for 8."