Microsoft is leveraging an outcry over Google’s approach to privacy to smear its rival in the press. It released a blog post yesterday that claimed to have fresh findings about how Google circumvents privacy protections in Internet Explorer to place cookies that track users across the web.

But Microsoft was playing dumb. It has known about this technique for two years and failed to mention that many other major sites like Facebook, in which Microsoft is an investor, use the same techniques to get around IE’s default privacy settings.

Here is the setup from Microsoft’s blog post yesterday, written by Dean Hachamovitch a corporate Vice President at Internet Explorer. “When the IE team heard that Google had bypassed user privacy settings on Safari, we asked ourselves a simple question: is Google circumventing the privacy preferences of Internet Explorer users too?”

That’s a question that Microsoft already knows the answer to. A study published way back in 2010 showed that more than a third of sites visited using Internet Explorer have a technical error that allows cookies to be installed. The study was big news, meriting a story in the New York Times.

The trick that Google, Facebook and many other are using to get around IE’s privacy settings involves a web standard know as P3P. In their recent blog post, Microsoft said they would be calling on Google to honor this protocol. But Facebook has made it perfectly clear that P3P isn’t some universally accepted technology. A blog post from technologist Nik Cubrilovic lays out the specifics. Attached to the piece of code that allows Facebook to get by IE’s privacy settings he found this statement:

“The organization that established P3P, the World Wide Web Consortium, suspended its work on this standard several years ago because most modern web browsers do not fully support P3P. As a result, the P3P standard is now out of date and does not reflect technologies that are currently in use on the web, so most websites currently do not have P3P policies.”

So to recap. Microsoft jumped on a story about how Google was getting around privacy protections in Safari to drum up outrage about a two-year old violation they were already well aware of. What they neglected to mention is that plenty of other sites, including Facebook and its Bing search data partners, use the exact same techniques and have more or less dismissed the standards Microsoft is calling on Google to honor.

This is playing politics with privacy concerns, plain and simple.