This fall, two compelling stories about politics and “big data” are playing out in the media. The first one you’ve already heard about: in the wake of Barack Obama’s re-election victory, The Atlantic, Time, and many other outlets have introduced readers to the hackers-turned-campaign-aides whose sophisticated algorithms underpinned the Obama campaigns’ data-driven voter turnout, persuasion, and fund-raising efforts.

The second story is lower-profile, though potentially no less significant: a congressional Bipartisan Privacy Caucus led by Reps. Ed Markey and Joe Barton is conducting an inquiry into the largely self-regulated companies that collect, analyze, and buy and sell personal data—much the same types of data the Obama campaign relied upon for its celebrated digital successes. After soliciting information from nine of those “data brokers” earlier this year, the caucus has asked those companies and federal regulators to attend a congressional briefing this week. (The Senate Commerce Committee opened a similar probe last month.) “I’m hoping to ratchet up the transparency so we can foster a system of oversight and consumer control over their data,” Markey told The New York Times over the summer.

But there’s less overlap between these two stories than you might expect. As Ad Age’s Kate Kaye pointed out in a November 16 article, even as members of the House and Senate examine data-handling practices that have much in common with those that played a prominent role during the election, the major data firms employed by the campaigns are not among those being scrutinized. “NGP Van, the Democratic data powerhouse favored by the Obama team was not part of the inquiry,” wrote Kaye, who is one of the most experienced reporters on the online political advertising beat. “Other political data firms left out of the inquiry include Catalist, another Democratic data firm; Campaign Grid, which offers Republican data and online ad targeting; and Aristotle, a well-established non-partisan political data company.”

That gap—between the growing importance of sophisticated data manipulation to high-level campaigns, and the scant oversight of the companies and practices that make that data-crunching possible—is at the root of an important challenge now confronting reporters. Some of the core functions of political journalism are to explain to readers what campaigns are doing, and to track—and, as needed, push back against—the messages campaigns disseminate. In a campaign that uses big data to deliver tailored messages, those tasks get harder, for reasons both technical and logistical. And when the use of that data isn’t transparent, they get harder still.

The tension between the rules that politicians propose for commercial data handlers and the ones they abide by themselves has been flagged a couple of times, by reporters on the lookout for it. As Kaye pointed out in the lead of her November 16 article, the Obama administration supports a Do-Not-Track protocol for Internet browsers “that, if pervasive, would throw a wrench into the data-collection tactics that empowered the campaign.” And back in March, a prescient piece by Politico’s Dave Levinthal noted the friction between the administration’s “privacy bill of rights” for Internet users and its own practices. The situation online mirrors the do-not-call registry overseen by the Federal Trade Commission; the registry exempts calls made by political campaigns, which are outside of the FTC’s jurisdiction.

It’s a dynamic that has some observers predicting that efforts to regulate commercial data mining, by the FTC or other agencies, are doomed to falter. It’s also one that galls privacy advocates, who worry that the political sphere actually creates special concerns warranting heightened scrutiny.

“There’s a unique danger with respect to heightened political data gathering as opposed to run-of-the-mill data for advertising,” said Dan Auerbach of the Electronic Frontier Foundation, an advocacy and litigation group. Political campaigns tend to want to keep data for longer time periods, Auerbach said, and to build more sophisticated personal profiles. He also pointed out that the lack of control citizens have over their own data when used by a campaign is “not in keeping with the principle of letting a user delete their own information” outlined in the administration’s Privacy Bill of Rights.

Sam Petulla is a journalist based in New York City and a graduate of the Columbia University Graduate School of Journalism. He covers technology, policy, and the awkward relationship between the two, and has written for The Atlantic, The American Prospect, Wired, and other publications.