A group of players in an online game, typically an MMO style game, who group and travel together for the sole purpose of ambushing smaller numbers of enemy players. The Gank Squad is often yelled at for using lightning-strike tactics and attacking with "overwhelming force", and is usually told (after having won a complete victory over a small group of poorly-defended enemies) that they must NEED to attack in a larger group in order to gain such victory.
"The 10 of us will run into the town all at once and kill those three saps."
"Man, that gank squad of 10 guys just killed all three of us! They're such noobs!"