A couple of decades ago, video games were much more solitary pursuits than they are today. Home console units meant you played by yourself or with a few friends as you passed a controller around or joined forces for a two-player game. Even with the original incarnation of the Xbox, the only way to link a large group of players was with a LAN party in someone's dorm. But thanks to Xbox Live and other online services, you can play with people anywhere in the world. This does, though, have some downsides: some of these people are among the most obnoxious humans you could hope to meet, and their anonymity only makes them bolder. Consider this list a guide to the various players you'll meet online. Forewarned is forearmed.