Used especially for online gaming, it is said to people whining which actually encourages them to whine more. It is used in a sarcastic and negative tone.
Gamer 1: Omg, you guys, they ganked me. Where were you?
Gamer 2: QQ Moar. We called mia.
Gamer 1: Q_Q
In response to whining, ask the recipient to whine even more (in online games).
Noob: omg we wiped all night on morogrim
Me: qq moar, it's an easy fight if you l2p