Not long ago, in one of the less inspiring episodes of our technology-intoxicated age, an act of canine defecation on a South Korean subway became global news. When an unrepentant dog owner refused to clean up after her wayward pet, another commuter took matters into his own hands, not by reporting her, but by posting a photograph of the offender (snapped with a cell phone camera) on a popular blog. The story and image spread quickly around the Internet, and a virtual public flogging ensued. When the woman’s identity was revealed, she was so ashamed she dropped out of university.

Law professor Daniel Solove begins his book, “The Future of Reputation: Gossip, Rumor, and Privacy on the Internet” (Yale University Press, 256 pages, $24), with the story of the haplessly named “dog poop girl.” It is, he writes, “just one example of a much larger phenomenon taking place across the Internet. Increasingly, people are exposing personal information about themselves and others online.” The aim of his book is to demonstrate “how the free flow of information on the Internet can make us less free.”

When early enthusiasts of the Internet were offering paeans to the medium’s power to transform culture, they tended to make anodyne promises about openness and connection. Today, however, with the rise of YouTube, blogs, and social networking sites, our digital global village has become something of a freak show: Fame (or notoriety — the two have become one) is bestowed on the self-filmed frolics of a pudgy adolescent pretending to be a Jedi knight — now immortalized on the Internet as the “Star Wars Kid” —or on a former Capitol Hill staffer, Jessica Cutler, whose blog, “Washingtonienne,” detailed her boyfriend’s penchant for spanking and her own forays into prostitution with married government officials. Mr. Solove has gathered a broad range of such vignettes from the virtual world, and in doing so forces readers to confront just how radically our understanding of reputation, identity, and privacy has been transformed in a brief span of time. Gossip, for example, need no longer languish among small groups of acquaintances. The Internet, writes Mr. Solove, “is making gossip more permanent and widespread, but less discriminating in the appropriateness of the audience.” The result is a world where stray rumors, which once had the lifespan of mayflies, now bedevil people for eternity. The Internet also offers new venues for public shaming, albeit often out of proportion with the original offense. As Mr. Solove notes, “People on the Internet move quickly, like a swarm of killer bees.”

Mr. Solove is moderately optimistic that the law can have some success taming this beast. His approach seeks a middle ground “between the libertarian and the authoritarian” approaches to new technologies. On Internet gossip, for example, he argues, “The law should view the placing of information online as a violation of privacy — even gossip that had previously been circulating orally in one particular social circle.” This sensible position is not likely to win him fans among radical free-speech advocates, but it is more sensitive to the real-world consequences of online gossip than current law.

But the law can only do so much. As Mr. Solove correctly notes, “The law is a puny instrument compared with norms.” Although Mr. Solove offers a good summary of how social norms change, his book would have benefited from a more sustained discussion of what he calls the “self-exposure” problem. Since our new social norm is self-revelation, does the exhibitionistic nature of the Internet undermine calls for privacy? One of the more chilling remarks included in the book is that of Jennifer Ringley, a student who installed a Web camera in her college dorm to broadcast her life. “I kept JenniCam alive not because I want or need to be watched,” she said, “but because I simply don’t mind being watched.” Mr. Solove argues that the architecture of sites such as the social networking hub Facebook discourages privacy, which is true, but he does not thoroughly explore the increasing narcissism of the generation being raised on these technologies and how that will affect their notions of privacy.

Mr. Solove’s sensibility is a good one — moderate, appreciative of the opportunities these technologies provide (he is a blogger himself), but not techno-utopian. Still, it is telling that Mr. Solove feels the need to remind us, “New technologies do not just enhance freedom but also alter the matrix of freedom and control in new and challenging ways.” Our culture’s insatiable techno-enthusiasm ensures that the burden of proof is on critics of technology to prove harm. As we begin to see more real-world lawsuits based on virtual activities (one recent case involved the activities of avatars in the online game Second Life), we will have to explore how our immersion in virtual space is changing our behavior — and how the law should deal with this.

“The key question is how much control we ought to have over the spread of information about us,” Mr. Solove writes. Perhaps the perennial risk of embarrassment and exposure is the price we must pay for the convenience and ease our technologies provide. We can summon facts from Google in a split second; but it is also a pitiless historian of our peccadilloes. As Mr. Solove’s thoughtful book reminds us, our technologies give us a heretofore-unknown level of control over information. But when it comes to our ability to manage information about ourselves — including the basic human need to defend our reputations — this control can prove illusory.

Ms. Rosen is a fellow at the Ethics & Public Policy Center in Washington, D.C., and senior editor of the New Atlantis: A Journal of Technology & Society.