We’ve told them once. We’ve told them twice. The third time, we’re bringing lawyers.

The Sunlight Foundation and the Campaign Legal Center, represented by Georgetown University Law Center’s Institute for Public Representation, are filing complaints Thursday with the Federal Communications Commission against 11 television stations for letting political advertisers flout federal disclosure requirements.

The Bipartisan Campaign Reform Act, passed with the support of both parties and signed into law in 2002 by then-President George W. Bush, requires individuals and organizations buying political commercials to provide certain basic identifying information for the TV station’s public file. All too often, that information — which can be key in helping voters make informed decisions at the ballot box — is being omitted.

We know this in large part because of two years of dogged work by the Sunlight Foundation’s Jacob Fenton, a reporter and developer who helped create Political Ad Sleuth, an online tool for crowdsourcing this critical information. Sunlight began work on this early in 2012 in partnership with Free Press to help identify the sources of money behind the political organizations — thinly disguised as nonprofits — that dumped at least $330 million into the 2012 campaign.

Political nonprofits, which often come with singularly uninformative names like “American Action Network” or “Patriot Majority USA,” are not required to disclose much of their spending — or any of their donors — to the FEC. But there is one place where they do have to leave a paper trail: the TV stations where they buy ads. That’s why we put our focus there.

We were in the midst of the project when we got a big break: an August, 2012 court ruling that allowed the FCC to require affiliates of the major broadcast networks (ABC, CBS, Fox and NBC) in the nation’s top 50 TV markets to post their files online. The online tool we were building was adapted to use metadata on those files, making them easily searchable and sortable. At the click of a mouse, you can see who is advertising in your backyard, or learn in how many TV markets your favorite dark money committee has been advertising. For the first time, reporters — and other members of the public — were able to easily examine documents heretofore only available to those who had the time to visit TV stations in person and pore over paper files.

Our effort (along with a similar one by ProPublica) yielded important information, helping to identify dark money spending and some of the sources of money behind it. But Fenton’s work maintaining our Ad Sleuth database also turned up something else: widespread violations of the minimal reporting requirements. The 2002 Bipartisan Campaign Finance Reform Act clearly states that political advertisers must identify:

• Their chief executive officer or board of directors (information that can go a long way to identifying the true agenda behind a vaguely-named group);
• Any issue of national importance to which the ad refers; and
• Any candidate to which an ad refers.

All too often, Fenton found, television stations (which are raking in tens if not hundreds of thousands of dollars from these ads) allow advertisers to get away without filling in such basic information.

Why is it important? Because “Americans for Better Apple Pie” might be your local slag heap operator. “Citizens for a Conservative GOP” might be Democrats trying to sabotage the primary contender that they think has the best chance of beating their candidate in the general. These are not far-fetched scenarios. Take a look at this ad, which doesn’t anywhere mention toxic materials, but which paint an indubitably positive picture of the chairman of the House committee that’s now working on a rewrite of the government law on toxic waste. Unless you are looking carefully at your TV screen at just the right time, you’d miss the fact that these ads are brought to you by the American Chemistry Council — an organization that is lobbying on the bill in question. Without the online TV ad files, you’d never know that the American Chemistry Council spent some $250,000 airing the ad.

But unless TV stations insist that advertisers comply with federal law, you won’t know anything at all.