The Information-Gathering Paradox - NYTimes.com SAN FRANCISCO - CONSUMER trust is a vital currency for every big Internet company, which helps to explain why the giants of Silicon Valley have gone to great lengths in recent months to show how hard they are fighting back against government surveillance. Companies have released transparency reports, many for the first time, enumerating how many times law enforcement agencies demand user data; their executives have issued blistering statements; and several firms, including Facebook and Google, have filed lawsuits in a bid to reveal more about secret government orders. All the while, though, a central contradiction has become ever harder to conceal. The Internet industry, having nudged consumers to share heaps of information about themselves, has built a trove of personal data for government agencies to mine - erecting, perhaps unintentionally, what Alessandro Acquisti, a Carnegie Mellon University behavioral economist, calls "the de facto infrastructure of surveillance." Nearly five months after Edward J. Snowden, the former National Security Agency contractor, went public with classified documents detailing the agency's widespread spying, the Internet industry has only sharpened its efforts to track users online, which it considers essential to profitability. Behaviorally targeted advertising is the principal revenue source for a host of online companies. Earlier this month Google announced plans to feature users" names, photos and posts to promote products in Web ads. Facebook recently expanded its search offerings and made it harder to hide from strangers trying to find you. Meanwhile, digital advertising networks are developing sophisticated new ways to track consumers on cellphones, gleaning intimate insights into who you are and what you like. And Twitter, which recently announced plans for a public offering, has partnered with a company that tracks whether ads on Twitter can influence what you buy offline. Commercial surveillance has been booming in recent months. "It's certainly striking to hear the companies" use of fiery rhetoric to criticize mass collection of bulk data since they themselves are engaging in mass collection of bulk data," said Woodrow Hartzog, who teaches privacy law at Samford University in Birmingham, Ala. The N.S.A. targeting has done nothing to dampen the appetite of private entities for information. There is a difference, of course, between government surveillance and commercial tracking, as Silicon Valley has been quick to point out. A coalition of technology industry associations appealed to the Obama administration in August not to confuse government surveillance with the tracking of users" data for advertising purposes. "Discussions about national security must be kept separate from conversations about commercial privacy issues, as the policy issues in these two areas are distinct," the coalition wrote in a letter to the White House. The core distinction, industry executives say, is that Web companies do not have the power to prosecute anyone, as law enforcement agencies do. Rather, the industry is trying to discover users" tastes and preferences, said Michael Moritz, a venture capitalist and chairman of Sequoia Capital in Menlo Park, Calif. "If you go to the heart of these companies, you have people wanting to make sure their products and services are as useful as possible to consumers," he said. They know that's the way they'll be able to flourish. The last thing they want to do is raise the ire of consumers. But hang on, critics say. Commercial data collection has its own dangers. As is widely known by now, posts on Twitter or Facebook can affect college admissions or prospects for employment. And the very collection of data by the likes of Facebook, Microsoft and Verizon creates a vast reservoir of information that intelligence agencies can tap into. In any event, the lines between the two sets of data, these critics say, are blurring. "I'm not saying evil corporations are doing this intentionally," Mr. Acquisti said. At the same time, their technologies have created this infrastructure, which makes universal surveillance possible. How much that will change consumer behavior is unclear. A Pew Internet Center survey in mid-September found that Americans were far more concerned about shielding themselves from advertisers than from government agencies. "The public is now starting to understand that there is aggregation of their information in public and private hands, and that may spark a serious debate that we need about privacy," said David Vladeck, formerly the chief of enforcement at the Federal Trade Commission and now a law professor at Georgetown University. Since the N.S.A. leaks began, several Silicon Valley companies have rushed to release reports listing how often governments around the world seek user data. The numbers themselves are revealing: Facebook received requests affecting over 20,000 accounts in the first half of 2013, Microsoft over 31,000 and Yahoo, over 40,000 accounts. The latest, LinkedIn, said it had received requests for just 97 users in the first half of 2013. "We regularly push back against improper requests for user data, including fighting requests that are unclear, improper, overbroad or unlawful," Ron Bell, general counsel at Yahoo, wrote in September, when the company released its first such report. Meanwhile, in an effort to allay public concerns, Facebook, Google, LinkedIn, Microsoft and Yahoo have filed suits in a secret federal surveillance court seeking permission to reveal the number and types of user data requests they receive specifically under national security laws, which come with gag orders. The companies hope to show that the requests affect a relatively small share of users. Facebook's chief executive, Mark Zuckerberg, has been among the most outspoken among his peers to criticize the N.S.A."s secret tracking program. "The government response was, "Oh don't worry, we're not spying on any Americans." " Mr. Zuckerberg said at a conference in September sponsored by the technology news site TechCrunch. Oh, wonderful: that's really helpful to companies trying to serve people around the world, and that's really going to inspire confidence in American Internet companies. A technology correspondent for The New York Times.