Perhaps you are familiar with an old saying: Even a broken clock is right twice a day. I've found that maxim valuable as I wade through the recent hand-wringing and recrimination among journalists and their critics over the fact that most mainstream media were slow to pick up on the story of corruption at ACORN.

New York Times ombudsman Clark Hoyt (a former colleague) and Andrew Alexander, his counterpart at The Washington Post, are among those who have asked whether that laggard performance reflects an unfortunate deafness to conservative media. As one of my readers put it, "There is a lot wrong with ACORN, and Fox was the only channel talking about it."

I might join this pity party if I thought Fox a credible news source. I do not. Consider just a few of the network's and its hosts' recent lowlights:

June 3 — In a column Bill O'Reilly says he never called murdered abortion doctor George Tiller "a baby killer."

This is wrong. PolitiFact.com has documented 24 instances just since 2005, of O'Reilly referring to the doctor as "Tiller the baby killer."

June 10 — Glenn Beck asks, "Why do we have automatic citizenship upon birth? We're the only country in the world that has it."

This is incorrect. Canada has it, as do 32 other nations.

June 18 — Sean Hannity says that under the Cash For Clunkers program, "all we've got to do is ... go to a local junkyard, all you've got to do is tow it to your house. And you're going to get $4,500."

This is false. The program requires the car to be drivable and to have been registered for at least a year.

July 22 — Beck says the director of the White House Office of Science and Technology Policy "has proposed forcing abortions and putting sterilants in the drinking water to control population."

This is untrue. The claim is based on a textbook John Holdren co-authored in 1977 that analyzed and "rejected" such coercive means of birth control.

July 31 — Kimberly Guilfoyle claims the government will get total access in perpetuity to the computer of any participant in the Cash for Clunkers program who signs up at the government Web site, cars.gov.

This is inaccurate. FactCheck.org reports this claim is based on a security notice required of "car dealers" who access a secure area of the Web site.

Let me make this next point crystalline; "every" news organization from CNN to CBS to Miami's Herald to L.A.'s Times gets it wrong on occasion, and every single report risks reflecting the biases — political, racial, religious, class, educational, geographical, generational — of the reporter. This will be true until the day the news business is no longer run by human beings.

But Fox is in a class by itself. In its epidemic inaccuracy, its ongoing disregard for basic journalistic standards of fairness, its demagogic appeals and its blatantly ideological promotions it is, indeed, unique — a news source in name only. That's not just an opinion: a 2003 study found Fox viewers more likely to be misinformed than those who get their news elsewhere.

Yet because this network that cries wolf, this network of birthers, terrorist fist bumps and tea party promotions, got it right for a change, mainstream media should wear sackcloth and ashes for their failure to take it seriously? No.

What missing the ACORN story suggests is a need for mainstream reporters to develop more sources among conservative activists and bloggers. But Fox forfeited any expectation of being taken seriously by serious people when it made itself an echo chamber less concerned with reporting news than with affirming the ideological biases of its viewers.

When faced with a broken clock, after all, the person who wants to know the time has two options: try to guess when the reading is right ...

Or get another clock.

Leonard Pitts Jr. is a columnist for The Miami Herald. His e-mail address is: lpitts@miamiherald.com. Leonard Pitts will be chatting with readers every Wednesday from 1 p.m. to 2 p.m. EDT on www.MiamiHerald.com.