This week we learned that the billionaire Koch brothers, David and Charles, have been discreetly bankrolling the supposedly grassroots Tea Party movement for over a year and that they really don't appreciate sudden public interest in the fact.

After all, it would be fair to say that many of the people who make a living writing about politics haven't even heard of them - and why should they? For most massively wealthy Upper East Side dwellers discretion is the watchword.

David Koch lives on Park Avenue in a 9,000-square-foot duplex apartment, a world apart from ordinary mortals. He's not used to public scrutiny, and boy he doesn't like it now it's arrived. All week David Koch has been slamming the 'liberal media' for doing their job and asking how much, where and when he and his brother have sprung to facilitate conservative causes.

Thankfully we already largely know. For years - decades actually - the Koch brothers, billionaire heirs of one of the largest privately held companies in the United States, have quietly promoted their hard-right ideology through third parties, think tanks, foundations and front groups.

Currently they influence the Tea Party through the Orwellian sounding organization with the almost laughable name: Americans for Prosperity. It makes you wonder why they didn't go the whole hog and call themselves Better Breaks For Billionaires.

This week they're howling about Jane Mayer, a staff writer at The New Yorker, who profiled the two brothers and their political connections in the magazine. They were particularly critical of her outrageous contention that their political interests 'dovetail with their corporate interests.' Why, the very idea. What a spurious charge.

In a way, you can almost feel their pain. I mean can't a man spend hundreds of millions quietly influencing elections from behind the scenes without being called onto the carpet by every two bit rag in the nation? Does living in Obama's America mean that someone so disproportionally influential now has to face this kind of scrutiny when they never have before?

Naturally, neither of the Koch's have ever attended a Tea Party rally or shouted themselves hoarse at a Town Hall meeting. There's no need to rally with the rabble when you know how to get results. Their father Fred Koch, rattled President Kennedy, funding the John Birch Society. The Koch brothers rattled Clinton, funding a lot of the attack groups and the rallies on Capitol Hill. Now they’re doing it to Barack Obama. And they’re going to keep doing it. Since 1998 Koch-controlled foundations have given out $196 million from 1998 to 2008, much of it to conservative causes and institutions.

But rather than discuss the brother's undoubted influence, conservatives have fired back by changing the subject and insisting that the Koch's exert the same kind of influence that George Soros does for liberal causes.

But you'd be quite hard pressed to uncover any major contribution from the Koch's to improve the lives of the downtrodden. In fact, they believe in minimal social services for the needy - no Social Security, no Medicare, no Health Reform - and much less oversight of industry. Not much bleeding heart to speak of there.

And now, by giving money to educate, fund, and organize the Tea Party protesters, Mayer suggests they have helped turn their own private agenda into a mass movement. Critics contend they are trying to shape and control a populist uprising to promote their own corporate interests.

But as Mayer has noted, that implies the Tea Party movement is a myth. Instead of being a bottom up uprising of engaged citizens and working stiffs, Mayer calls it a massive, well financed political campaign against Obama and the Democrats, in part funded by the brothers who run America's second-biggest private company, Koch Industries.

This may give short shrift to the very real (and often divergent) passions animating the Tea Party, but it doesn't invalidate Mayer's contention. It's almost sad, in a way, to acknowledge that after a year of angry grandstanding from coast to coast the Tea Party is turning out to be just another corporate-backed attempt to influence policy to help big businesses make more money.

Americans for Prosperity are no doubt quite sincere in their goals, but it might be wise, in the coming months, to ask them exactly who's prosperity they mean.

UPDATE: This morning Americans for Prosperity (AFP) launched $500,000 worth of new TV ads in Arizona targeting Democratic Representatives Ann Kilpatrick, Harry Mitchell and Gabrielle Giffords is the latest indication that conservative group will be a major player in the November midterm elections.

The new Americans For Prosperity ads come a week after the group's sister organization, Americans for Prosperity Foundation, announced plans to launch a $4.1 million ad campaign targeting 24 competitive House seats in 11 states - a buy that will probably be the biggest of the summer.