An author's purpose is often to get us to think more deeply about a topic. rosen does this in her article when she writes

a.) as with any new technological advance, we must consider what type of behavior online social networking encourages.
b.) by contrast, today's social networking sites organize themselves around metaphors of the person, with individual profiles that list hobbies and interests.
c.) indeed, media coverage of social networking sites usually describes them as vast teenage playgrounds—or wastelands, depending on one's perspective.
d.) the delphic oracle's guidance was know thyself. today, in the world of online social networks, the oracle's advice might be show thyself.