Imagine Charles and David Koch testifying, under oath, in Congress.

Even though the billionaire oil industry brothers continue trying to dodge accountability, Rep. Henry Waxman (D-CA) invited the Koch brothers to testify and answer a few simple questions about how the Kochs are positioned to gain financially by the Keystone XL oil pipeline, a 1,700-mile long boondoggle that would make the Koch brothers even richer.

There's ample evidence linking the Kochs' business to the Canadian tar sands, which is the dirtiest energy in North America. Indeed, the Koch brothers' stand to be among the pipeline's biggest beneficiaries. Even the Koch brothers' website confesses to being a party to tar sands oil.

The Koch brothers are doing whatever they can to avoid testifying in Congress, despite the fact that the Kochs informed the Canadian government of their "direct and substantial" interest in the pipeline. Waxman has been trying to get answers from the Koch brothers since last spring, but the Kochs have not cooperated.

At the same time, the Kochs' allies in Congress are doing their best to stonewall oversight. This outcome doesn't surprise me one bit given the Koch brothers' near-monopoly on the influential and powerful House Energy and Commerce Committee. According to the Los Angeles Times, Koch Industries and its employees are the single largest oil and gas donors to the committee. They've contributed $279,500 to 22 of the committee's 31 Republicans and $32,000 to five Democrats. Talk about the best democracy money can buy!

In the 2010 elections that gave the Republicans the majority in the house, many of these committee members were ones who owed their electoral fortunes to the Kochs or groups affiliated with the Kochs. One representative hired a Koch Industries lawyer after election day. Another needed a lift from the Koch brothers' Tea Party group, Americans for Prosperity, to unseat an incumbent. No matter how you slice it, the Koch brothers have their fingerprints, not only the oversight of the Keystone XL pipeline, but on the pipeline's profits.

Since last year, the Koch brothers have attacked those in and out of Congress who're merely trying to find the truth. And sorry Charles and David, your word alone is no substitute for the truth.

So what are the Koch brothers hiding? It's time to stop whispering and start shouting. Insist the Koch brothers testify before Congress.

The Keystone XL pipeline is but another example of the Koch brothers use their wealth to advance policy that makes them richer. Their wealth enables them to write the script for politicians and others to follow.

Sunlight is the best disinfectant. If you're like me and are demanding truth, I invite you to help us shine a light on the Koch brothers position on the Keystone XL oil pipeline but signing our petition to leading members of Congress.