Heh, I got a game a few days back. I was paired with a (somewhat noob) Terran. Halfway through the game, he suddenly shouted, ROACHES! I took a quick look at the opponent zherk base, but no sign of roaches or anything.

When asked how he knew, he said "SCAN!" (aye he was typing in caps the whole game, very annoying.) Obviously he was lying, since I saw no sign that he scanned the base and his OC had 80+ energy. True enough the zherk player tried to nydus our base with roaches.

Even if we won the game, that incident was enough to sour the victory.