What happened next is a tale of the system working. Because that misleading ad was made not by a candidate but by a third-party group, a category that includes political parties, interest groups and super PACs, Ohio TV stations had a right to refuse it. When they learned about the duplicitous editing, a number of them did exactly that. Their actions remind us that although, with few exceptions, broadcast stations have to air ads sponsored by federal candidates, they can reject outside groups' ads or, if they choose to air them, insist that they stick to the facts.

More from the AARP Election 2012 Blog

The Annenberg Public Policy Center has a website viewers can use to protest the ads with their local stations, which have the power to reject them. — iStock

When the fire broke out, there wasn't a moment to spare," said 78-year-old Ohioan Marlene Quinn in a Web video last October. "If not for the firefighters, we wouldn't have our [great-granddaughter] Zoey today. That's why it's so important to vote no on Issue 2." Within days, her video had been repurposed by a group favoring the Ohio ballot initiative to make it appear she supported the law that she wanted repealed. "She's right," said the deceptively edited ad. "By voting no on Issue 2, our safety will be threatened."

This year has seen an unprecedented amount of third-party advertising. By May 10, 534 groups organized as super PACs reported receiving $204,323,416 and spending $99,803,597 in the 2012 cycle, according to OpenSecrets.org. The level of inaccuracy in the third-party presidential ads has been high. As an Annenberg Public Policy Center study shows, from the Iowa caucuses through the Wisconsin primary, almost 57 percent of the $41.1 million deployed by the four highest-spending third-party groups was devoted to 19 ads containing misleading claims.

The deceptions were of the sort that shift votes. Imagine a potential supporter of Mitt Romney accepting at face value the false implication in an American Federation of State, County and Municipal Employees ad that he engaged in Medicare fraud at a company owned by his Bain Capital firm. Or imagine a person who opposes abortion mistakenly believing a pro-Romney super PAC's false allegation that former House Speaker Newt Gingrich supported legislation facilitating abortion in China.

It's not hard to imagine a voter, misled by such claims, rejecting a candidate she would otherwise support.

Because they can charge more for third-party ads than for those by federal candidates, stations earn a windfall airing them. As CBS President Les Moonves told an entertainment law conference in March, "Super PACs may be bad for America but they're very good for CBS." But by taking seriously their right to insist on the accuracy of third-party ads and regularly debunking deceptive political ad content, stations can translate some of those profits into protection for the public served by their stations. That is what a new campaign by the Annenberg Public Policy Center (APPC) of the University of Pennsylvania is asking them to do.

Go to the "Stand by Your Ad" page at APPC's FlackCheck.org and email your local station managers. Encourage them to protect their viewers from air pollution. The process takes less than two minutes. More than 900 of the 1,047 station managers have already heard from their viewers. Please make your voice heard now.

Kathleen Hall Jamieson is director of the Annenberg Public Policy Center of the University of Pennsylvania.

Also of interest: Are new voter identification laws fair?