News today that the FTC is preparing to issue civil subpoenas as part of a broad anti-trust inquiry into Google’s business practices comes on the heels of a similar–and perhaps more in depth– threat from Congress.

In a letter sent to Google on June 10, the Senate Subcommittee on Antitrust, Competition Policy, and Consumer Rights Senators Herb Kohl (D-WI) and Mike Lee (R-UT) requested the company provide one of their top two executives to testify at an oversight hearing exploring Google’s business practices.

But so far Google has refused and offered to send their legal counsel instead prompting the Senate subcommittee to threaten subpoenas to compel either Larry Page or Eric Schmidt to appear.

It will be interesting to see how Google responds to the FTC subpoenas. But in the case of Congress, Google’s sudden interest in privacy is irony at its best.

Google has historically taken an approach to privacy and property rights that can be called cavalier at best. Whether its secretly capturing data from unsecured WiFi networks, uploading books without permission, or using personal data to launch a new social platform without users’ permission Google has seemingly held privacy in low regard.

In fact, Google has become a juggernaut in the Internet advertising and search markets by capturing and using the personal data of every person who uses any Google product. Every Gmail sent, every Google search and every GoogleDoc created are stored on Google’s servers–forever. This massive cache of data enables Google to create consumer profiles and behavioral models that are highly valued by advertisers.

Google has made billions peaking behind your curtains or as Schmidt calls it get ting “right up to the creepy line” and then using what they find there. But now that Congress and potentially the FTC is poking around their curtains, Google seems to suddenly value privacy.

Google’s change of heart is even more ironic when you consider the advice Eric Schmidt offered in December 2009 in response to those expressing privacy concerns in relation to the government:

“If you have something that you don’t want anyone to know, maybe you shouldn’t be doing it in the first place. If you really need that kind of privacy, the reality is that search engines–including Google–do retain this information for some time and it’s important, for example, that we are all subject in the United States to the Patriot Act and it is possible that all that information could be made available to the authorities.”

Google’s seeming reluctance to have their top executives testify as executives from so many other companies have done in the past leaves the impression that there is something they don’t want us to know. Which of course begs the question: what is it they shouldn’t have been doing in the first place?