Microsoft wrapped up a three-day campaign on Friday against rival Google by claiming its newest browser, Internet Explorer 9 (IE9), is superior in stopping users from being tracked by online advertisers.
"We had some fun this week," said Frank Shaw, Microsoft's head of corporate communications, in a blog post Friday.
Earlier in the week, Microsoft ran full-page advertisements in the New York Times, the Wall Street Journal and USA Today that took advantage of controversy over a recent announcement by Google of changes to its privacy policies.
The first advertisement appeared in newspapers on Wednesday, with a second on Thursday that compared Microsoft's Hotmail and Office 365 to Google's Gmail and Docs.
"The changes Google announced make it harder, not easier, for people to stay in control of their own information," argued Shaw on Wednesday. "We take a different approach."
Elsewhere, Microsoft has asserted that Google's only real customers are its advertisers - implying that the California search giants cares less about users than it does ad sellers.
Google, which announced the changes last week, said they were designed to consolidate user information across its many services. The policy rewrites will go into effect next month. Google has already defended the changes in letters to the U.S. Congress and European Union regulators .
Today, Microsoft ran a third advertisement that touted IE9's "Tracking Protection," a feature the company debuted at the March 2011 launch of the browser. Tracking Protection relies on published lists that selectively block third-party sites and embedded content to disable advertisers' tracking of users' movements on the Web.
Shortly after IE9's launch, Microsoft also added support for another solution, dubbed "Do Not Track," to follow in Firefox's footsteps.
In Friday's ad and supporting blogs by Shaw and Ryan Gavin, the general manager of IE marketing, Microsoft positioned IE9 as the application users can run to "browse without being browsed."
Google has not rolled anti-tracking technology into its Chrome browser, but last year did release a browser extension called "Keep My Opt-Outs" that blocks targeted ads produced by about 60 companies and ad networks that hew to self-regulation efforts by the online advertising industry..
Although Microsoft has taken to touting IE9's uptake among Windows 7 users only - it's repeatedly said that that metric is the only one it watches - Internet Explorer has failed to maintain its share of the browser market as Google's Chrome has stolen users.
According to Web measurement firm Net Applications, all versions of IE lost 7.4 percentage points of share during 2011, representing a decline of 12.5 percent for the year. Meanwhile, Chrome boosted its share by 8.8 points in the same period, for an 85 percent jump.
Worldwide, IE9 accounts for 11.6 percent of all browsers on all desktop operating systems. IE8, the 2009 browser that lacks Tracking Protection, has more than twice that share.
Earlier today, Germany's Federal Office for Information Security recommended users run Chrome, not IE, Firefox or other browsers.
Shaw may have made light of the campaign with his "had some fun" comment, but Google was not amused: On Wednesday, Google policy manager Betsy Masiello countered by saying that "a number of myths are being spread about Google's approach to privacy."
Masiello singled out Microsoft's attack ads in one of her fact-versus-myth bullet points.
"We don't make judgments about other people's policies or controls," said Masiello. "We've always believed the facts should inform our marketing - and that it's best to focus on our users rather than negative attacks on other companies."