Feed - M. T. Anderson

In this satire set in the future, most people have computer "feeds" in their heads to control their environment, tell them where to party on the moon, and how to accessorize the mysterious lesions everyone's been getting, and pretty much tell them how to think and live. Titus meets Violet, an unusual girl who is in serious trouble, and learns she has decided to fight the feed because she cares about what's happening to the world.