(CBS News) The claims and counterclaims the candidates rattle off provide endless TALKING POINTS to the pundits . . . and plenty of work for eager fact-checkers. Rita Braver has been out searching for Just The Facts:

"That's not true!"
"That's not true!"
"You've got your facts wrong!"
"I never said that."

The candidates may constantly challenge each others' claims, but as each debate rages on, legions of truth-seekers are dissecting their every utterance.

Like those from FactCheck.org, at the University of Pennsylvania's Annenberg Public Policy Center.

"They say so much," said Braver. "How in the world do you keep up with it?"

"Triage!" laughed former investigative reporter Brooks Jackson, who has been director since the project started in 2003.

"It's basically journalism," he said. "We go to the most authoritative sources of facts that we can find. If it's a claim about jobs, we'll go where the economists go - the Bureau of Labor Statistics - and download the data ourselves and check it out."

Case in point from this past Presidential Debate:

Romney: "In the last four years women have lost 580,000 jobs."

FactCheck.org found "the figure is closer to 93,000."

Of course, President Obama came in for criticism, too, referring to an Arizona law that allows police to stop anyone suspected of being an illegal immigrant.

Obama: "He called the Arizona immigration law a model for the nation."

But FactCheck found that Romney was referring to an earlier, less stringent law "requiring EMPLOYERS to check the immigration status of EMPLOYEES."

Throughout the campaign, Jackson says there have been complaints and pushback from both camps.

"We got a six-page letter from the Obama campaign, complaining about a ruling we had done," Brooks said. "We do get it from both sides. And I think that shows we irritate Republicans sometimes and we irritate Democrats sometimes."

Of course, FactCheck is not the only lie detector out there.

The Tampa Bay Times has its Pulitzer Prize winning "Truth-O-Meter," with the popular "Pants on Fire" for the worst falsehoods. You can even get it as a phone app!

And most networks, including CBS News, have fact-check operations.

But candidates have used fact-checks to try to game the system.

After the first debate, the Obama campaign quickly put out an ad with NBC's Andrea Mitchell disputing Romney's claims about his economic plan:

Mitchell: "The non-partisan tax policy center concluded that Mitt Romney's tax plan would cost $4.8 trillion over ten years."

NBC quickly objected, saying Mitchell's report was also critical of Obama's claims.

David Corn, Washington Bureau Chief of Mother Jones Magazine, recently wrote a column questioning whether fact-checkers have become "merely participants in the ever-roiling political tussle."

"They find it useful to use them as ammo, but not useful to abide by them," said Corn.

But David Corn worries that, in general, many mainstream fact-checkers are too concerned about finding an equal amount of falsehoods by each candidate.