Many local television stations do not consistently evaluate the accuracy of the political ads they air, according to survey results released Tuesday by the Annenberg Public Policy Center.

As Annenberg director Kathleen Hall Jamieson acknowledged, the center’s study, released during a mini-conference at the National Press Club on factchecking and the 2012 election, is of limited utility: the data was collected via an opt-in survey of 206 U.S. TV station managers and executives, and, as such, the findings can’t really be generalized. Still, the study suggests that many station managers and executives are unclear about their rights and responsibilities when faced with a political ad that takes liberties with the truth—in particular, whether they can refuse to run certain questionable ads, or suggest edits, or otherwise factcheck the content before it airs.

At the conference, panelists revealed that some stations are already reporting ad space being reserved as far ahead as October. As one station manager told Mike Cavender, executive director of the Radio Television Digital News Association and Foundation, “We’re running around with a bushel basket, trying to catch all the money that’s falling out of the sky.” (For an in-depth look at how this money gets distributed across the local TV industry, see this recent piece by CJR’s Erika Fry.)

When those ads are purchased by candidates whose campaigns are eligible for federal funding, broadcasters are required by the FCC to run them, with limited exceptions. Stations can suggest edits, but candidates are under no obligation to heed them. This “no censorship” rule is designed to prevent stations from favoring one candidate or party over another.

But much of the money now being spent comes from third-party organizations, like super PACs backed by wealthy donors (or, to a lesser extent, by corporations enjoying the speech freedoms confirmed by Citizens United). And the “no censorship” rule doesn’t apply to these third-party ads—stations can refuse to air those spots without violating any law.

And because stations control something—access to the airwaves—that super PACs badly want, they can generally do so without risk to their ad revenues, as well. As David Bradley, general manager for an Ohio station, told CJR’s T.C. Brown in March, “We don’t doubt at all if we turn down an ad for whatever reasons, deceptive claims, [the super PAC] will be back with a different version the next day.”

Yet of the 206 station managers surveyed by Annenberg, only 56 percent said they screen the accuracy of third-party ads. And just thirteen percent of the respondents said their stations had refused to air at least one third-party ad during the past 12 months.

During that time, of course, journalistic factcheckers have found plenty of other ads factually wanting. And Annenberg’s “Stand By Your Ad” campaign, an outgrowth of its site, has been reminding station executives that they can, in fact, push back on questionable content, while spotlighting specific ads it sees as false or misleading.

But a panel comprised of two station executives and a media lawyer made clear that those in the industry set the bar for refusing an ad higher than watchdog groups do. When third-party organizations send their ads to the stations, they usually include documentation for every claim made by the ad, and this documentation is typically good enough for stations. “If there’s a substantiation for the claim, and if this claim falls in the realm of reasonable political debate, it’s going to get approved,” said Kevin Keeshan, ombudsman for the standards and practices department at NBC News. “We don’t make judgments on opinions. We take a look at what’s said, and if there’s substantiation for it.”

“The sweet spot is whether [an ad] falls in the bounds of reasonable debate,” said Keeshan, and “reasonable debate” is broadly defined. “Everybody who watches political ads is watching them through a different filter. I’m not sure we can weigh in in a way that’s going to be satisfactory to all parties.”

The panelists also said that, given resource limitations, they can’t be expected to independently factcheck every political ad their stations run. “In any given week, I will have six candidates on the air with maybe four different ads; you’ll have five super PACs…” said Susan Petro, political specialist at Washington, D.C.’s WJLA-TV.

Of course, the editorial side at these stations can also take on misleading ads. Indeed, another panel at the conference featured three local TV journalists who supervise factcheck segments on their news broadcasts.

Justin Peters is editor-at-large of the Columbia Journalism Review.