Here´s some of the game´s background story:

...Anarchy Online is based around a conflict between the totalitarian Omni-Tek corporation and the small rebel Clans fighting against them, and when you start the game you can either remain neutral or choose to join one of these factions. This decision will have a big impact on how the game is played, as well as determining where in Rubi-Ka you start out. Whichever side you sign up with though, you will need to work with the other players in your faction to get the most out of the game. Players can team up temporarily to go hunting and share the experience from their battles, and more permanent allegiances are also possible thanks to an advanced in-game clan system...