The decision was, if I'm understanding it correctly, that the law was unconstitutionally vague, and gave law-enforcement way too much latitude in deciding which images "appeared" to place what "appeared" to be underage models in a pornographic context. Specific to CG, the court also decided that the criminalization of "virtual" childporn--that which uses no actual children--essentially creates a class of illegal thought; a bit too 1984, even for this very conservative court. The 1st amendment exists to protect unpopular and subversive ideas--and since there are no victims, the court says there's no crime. I'm no purveyor of child-porn, but I'm glad to see an end, at least temporarily, to all the completely loony hysteria around this issue.