WASHINGTON, DC — So-called “behavioral targeting” — or serving ads to Web users based on their surfing habits — is under scrutiny by the Federal Trade Commission. The inquiry could shape not only advertising, but the character of the Web itself, according to pundits.Here’s the core issue: Public interest groups complain that behavioral targeting violates surfers privacy, because in most cases it’s accomplished without surfers’ knowledge or consent. In addition, with daily growth in the massive amounts of supposedly anonymous data about search results, Web pages and shopping habits, anonymity is at risk just by the law of averages. “Ego searches” — in which users enter their own names into search engines to see if they appear anywhere on the Web — represent only one example of the kinds of personally identifiable information that inadvertently can be attached to the random numbers generated to identify behavioral information.

In addition, “It is not anonymous if the companies are tracking the same user over time,” Ari Schwartz of the Center for Democracy and Technology told the Washington Post. The CDT has filed comments with the FTC.

Consumers have voiced concern about the practice, as well. A March poll by Harris Interactive showed 60-percent of surfers dislike the idea that websites may use information about their online activities to tailor ads or content to them.

Advertisers and publishers, however, say that without targeted ads, free content on the Web may disappear. In the face of a consuming public that is increasingly reluctant to pay for online content, Web publishers have been trying to fill the gaps in their budgets with advertising revenues. Advertisers are willing to pay more for audiences that meet certain demographics, and behavioral targeting allows them to put their money where they think it will do the most good.

In short, behavioral targeting is a means of quantifying the unquantifiable whims of the cyberscenti by directing advertising based not on a Web page’s content, but on who’s looking at it. The practice promises to bolster advertising revenues across the board in an economy that’s otherwise sagging.

Is there some middle ground? That’s what the FTC wants to determine.

For now, the federal regulator is considering voluntary guidelines that would establish some parameters for behavioral targeting. In a draft of the guidelines, the FTC specified clear warnings about tracking and called for a method that would allow users to opt out.

Federal and state lawmakers are champing at the bit to make at least some of the guidelines mandatory.

The Newspaper Association of America already has filed a brief with the FTC saying some of its proposed guidelines may violate the First Amendment.

“The problem for newspapers is that a story headlined ‘Two Dead in Baghdad’ isn’t very [advertising]-friendly,” Kent Ertugrul, chief executive of Phorm, a behavioral targeting company working with British newspapers, told the Post. “But if you know who is looking at the page, that’s where the opportunity is.”