Is it really surprising that the brotherhood of hackers turns out to be more like central intelligence? It doesn’t take much of an imaginative leap to go from gathering every last move you make online, and sharing it with marketers and advertisers, to divulging it to spies. Google, Apple, and Facebook have long since stopped being mere instruments of individual empowerment through collecting and processing information. Benignly democratic terms like “open source” and “transparency”—still in ubiquitous use around Silicon Valley—have become outmoded distractions from the source of the tech giants’ phenomenal growth, which is data-mining and its monetization.

Yes, it’s voluntary—no one forces you to enter credit-card information on Home Depot’s Web site, or to let Facebook track every purchase you make on Amazon—whereas Prism, the N.S.A.’s top-secret program for mining e-mails, videos, chats, and other online communications, is not. Markets involve choice; laws do not. Being a consumer is discretionary; being a citizen isn’t. But Prism, for all its breathtaking reach and intrusiveness, is less creepy to me than all the trillions of bits of information that commercial companies have stored up on all of us, gathered through a sophisticated mix of temptations, deceptions, default settings, carelessness, and sheer market power. It’s sinister when Big Brother is watching you, but it’s even more sinister when Big Brother is you, sharing. Prism is designed to prevent terror attacks on Americans. Advertising algorithms are designed to increase Google’s and Facebook’s profits. Which involves more of a public benefit? Between career officials at the N.S.A. and marketing managers at social-media companies, I trust the former more than the latter to maintain my privacy and use the information they have on me with maximum restraint. (Private contractors like Booz Allen Hamilton are a different story—the outsourcing of national security is one of the worst post-9/11 trends.)