But Microsoft Internet Explorer general manager Dean Hachamovitch advises to remain calm. "The point isn't to block content or ads. The point is to put users in control of what they're sharing," he said, adding he has read and heard many misconceptions about what InPrivate can and cannot do.
For instance, the InPrivate Browsing feature -- already slang-termed "porn mode" -- only allows a user to hide single browsing session activities from "over the shoulder" viewers such as family members. It does not block ads from being served to the user or from advertisers counting views or clicks.
It works, and got its nickname, by letting users surf porn sites (or any other content, for that matter) without caching any content such as a list of URLs visited, cookies or other data. That could mean no cookies on your computer -- as well as no cookies for future use by marketers or publishers, although only during selected InPrivate sessions.
However, it is the InPrivate Blocking feature that seems potentially more worrisome for advertisers. InPrivate Blocking acts to inform users about sites that consistently track and collect browsing histories. In fact, when a user opts into an InPrivate session, it will automatically block third-party content if it detects that the third party has "seen" the user more than 10 times. So, for instance, if the third party is advertising.com and it is serving ads across 10 sites a user has visited during an InPrivate session, it will begin to block advertising.com tracking codes and possibly content on the 11th website.
Cause for concern
Mike Zaneis, VP-public policy for the Internet Advertising Bureau, said while he is encouraged that InPrivate is never a default option on Internet Explorer -- meaning that users have to manually opt in each time -- he still has concerns.
"With IE's market share, will so many people activate that so that it could affect the revenue side of the industry?" he asked. "Any content from anywhere that appears as third parties, whether advertising or stock tickers or news feeds, all appear as third parties, and in theory their content could be blocked.
"And if you're blocking all third parties, you're also going to block all analytic companies," he said. "You'd be blocking the companies that do the auditing of ad delivery." He's particularly concerned about the potential disruption to the entire accounting system of internet advertising.
Mr. Hachamovitch concedes that IE 8 has no way of knowing if the content is an ad, a stock tracker or a newspaper column. It can only tell if it is third-party content. So that does mean that any content, say, ads, analytics and more, can be blocked. However, he repeated that the user must select InPrivate every time. And users can create "allow" and "block" lists, so-called whitelists and blacklists, to always allow content from trusted sources. Consumers can also subscribe to lists of acceptable content created by others.
Microsoft itself has tips for publishers and advertisers on how to get third-party content and ads seen. Publishers, for instance, can serve the ads directly from their site (making them first-party content) or they can make third-party content look like first-party content, he said.
Letting consumers decide
Ultimately, the point of InPrivate is not to block anything, but instead to give consumers control of the online information they chose to share, or not, Mr. Hachamovitch said. "In a world of well-informed consumers who expect choice, we all need to be thoughtful about how we conduct business," he said. "To me, this really starts the conversation. IE8 Beta 2 starts us thinking about the expectations people should have about what they share and how."
Of course, Microsoft is hardly anti-advertising, and in fact, depends on ad-servicing revenue from its own sites like MSN. In May 2007 it purchased for $5.9 billion aQuantive's three businesses -- Atlas, DrivePM and Avenue A -- as a means to build out a massive ad platform, and it had pursued Yahoo in a bid to gain more display-ad leverage. Microsoft, moreover, is a longstanding member of the IAB.
"From the Microsoft perspective," said a spokeswoman, "we're right there with the rest of the crowd in that we think there is a lot of benefit in targeted ads. We just believe consumers have the right to know it's happening and to opt in."
JupiterResearch analyst Emily Riley said the industry upheaval may be moot soon enough anyway, as ad targeting has come under serious scrutiny from the Federal Trade Commission. She said she believes the many different industry factions will come up with -- by force or free will -- guidelines and standards that are acceptable to consumers and regulators.
"In the short term, though, I can understand how it could be scary for advertisers, because ad targeting is so valuable," she said.