On July 28, 2014, Rep. Bill Shuster, R-Pa., the powerful chairman of the House Transportation and Infrastructure Committee, called for a vote on a bill he’d sponsored, the Transparent Airfares Act. Forbes contributor Andrew Bender, who writes regularly on travel, noted that it “does the opposite of what the name implies” — but it garnered 50 co-sponsors including former presidential candidate Michele Bachmann, R-Minn., current House Financial Services Chair Jeb Hensarling, R-Texas, and the current ranking member of the Transportation Committee, Peter DeFazio, D-Ore. The bill passed the House on a voice vote.

Shuster’s measure, which died in the Senate, would have allowed airlines to exclude things like federal fees and taxes when telling customers the price of an airline ticket. So that $350 round trip special to Las Vegas could result in a $500 or more charged to a flier’s credit card. While consumer groups hated the bill, it had one fairly important backer — Airlines for America, an industry trade group that represents 11 U.S. airliners including passenger giants United, American Airlines, Delta, Southwest, USAirways and freight carriers FedEx and UPS. Its members collectively contributed about $8.8 million to federal political committees in 2014.

Airlines for America is also the group that employs Shelley Rubino as its “Vice President, Global Government Affairs” (titles for lobbyists get fancier all the time). Rubino and Shuster, according to Politico’s account, started a romantic relationship in the summer of 2014. The same summer he moved the Transparent Airfares Act. Neither the public nor consumer groups nor close observers of the travel industry like Andrew Bender had any idea of the close relationship between the lawmaker and the lobbyist; which, when one thinks about it, is par for the course in the world of K Street, which operates far more in shadows than sunlight.

How lobbyists impact policy — their effectiveness — is a huge unknown, even to informed insiders. For example, a few reporters who closely cover health care issues were taken by surprise by the announcement of the deal to change the caps on Medicare payments to doctors, hammered out in secret between House Speaker John Boehner, R-Ohio, and Minority Leader Nancy Pelosi, D-Calif. But their lobbyist sources, by contrast, were all well-informed about its particulars and how it was arrived at on the day it was announced.

Even how much interests spend on lobbying is murky. Our friends at MapLight.org, a group that studies the intersection of money and politics with legislative activity, released a chart showing the organizations that disclosed spending the most on lobbying in the first three months of 2015. Of the 10 biggest spenders, just three — Google, the Pharmaceutical Research and Manufacturers of America and the American Hospital Association — calculate their spending using the definition of lobbying set out under the Lobbying Disclosure Act. The other seven, including the U.S. Chamber of Commerce, the American Medical Association, General Electric and American Electric Power, use a definition of lobbying from the Internal Revenue Code, section 162(e) if you’re keeping score at home.

The tax code doesn’t allow corporate deductions for their political activities, which include things like grassroots lobbying, lobbying state governments, contributing (where legal) to state and local political parties and candidates, and even paying dues to lobbying organizations like the U.S. Chamber of Commerce. So when a company like General Electric reports its lobbying spending, it’s including things like its campaign contributions (the company disclosed giving more than $890,000 to political committees in 2014) and the portion of its dues spent on politics by organizations like the U.S. Chamber of Commerce (which of course reports that money in its own total lobbying spending).

Even worse, what they’re really spending their money on is a matter of guesswork. In its most recent disclosure, General Electric lists 84 specific issues they lobbied on — and one monetary total. There’s no way to tell whether the company put more effort and time into the tax on medical devices, funding for the Overseas Private Investment Corporation or modifications to the B-1 bomber.

Even if we did have more granular information on what lobbyists do, we still wouldn’t know what level of access lobbyists get to lawmakers and their staffs. So while the Shuster-Rubino story tells us much about Shuster, there’s a much wider world of information on lobbying that needs to be disclosed.