On the prowl for the best deals from U.S. retailers this Thanksgiving weekend? A quick check online can provide the answers that retailers are not yet ready to reveal.

Numerous Web sites have cropped up in recent years that publish in advance what they claim are copies of the newspaper ads retailers will run for Black Friday — the day after Thanksgiving, which marks the chaotic and ultra-competitive launch of the holiday shopping season.

A visit to BlackFriday.info reveals that Circuit City Stores Inc. (CCY) will be selling an Olevia 32-inch high-definition LCD TV for $499 from 5 a.m. until 11 a.m. on Black Friday, while Sears will sell a men's leather coat for $49.99.

Another Web site, Black Friday Ads says Wal-Mart Stores Inc. (WMT) will be offering a 42-inch high-definition plasma television for $988 from 5 a.m. until 11 a.m., while supplies last, on November 24.

Jon Vincent, founder of BlackFriday.info, said he gets copies of the ads from employees working at newspaper distribution facilities, who take snapshots of the inserts and send them to his site.

Vincent said he does not call the retailers to verify the information, but he makes sure the pictures look legitimate and the prices seem reasonable before posting them.

"People are really interested to find out what's on sale on Black Friday," he said. "If they know a plasma TV is going to be on sale for $500 off, they're not going to buy it now, they'll just wait until Black Friday and then they'll buy it then."

But retailers are not happy having their holiday sales plans revealed ahead of schedule to either shoppers or to their competitors.

Black Friday Ads said privately held home goods retailer Linens 'n Things sent a letter asking it to remove the information from the site or it would take legal action.

Linens 'n Things did not immediately return a phone call seeking comment.

BlackFriday.info had a note on its site on November 13 saying it had removed a Best Buy Co. Inc. (BBY) advertisement after the electronics retailer threatened to try to shut the site down.

"We can't really fight Best Buy," Vincent said.

A Best Buy spokesman said he was unaware of the note posted on BlackFriday.info, but said the retailer does not acknowledge or comment on "rumor" sites.

But it is hard to make the information disappear once it is online.

The day after BlackFriday.info removed the Best Buy ad, Black Friday Ads had a copy of what looked like a Best Buy newspaper insert, promoting a 42-inch LCD high-definition TV for $999.99, after $500 in instant savings, until noon on Black Friday.

BlackFriday.info's Vincent said this is the third year his site has published Black Friday deals. While every year one or two retailers complain, he does not expect that to hinder these sites.

"Retailers have had power for so many years and now with the Internet, you can share all this information and it really gets more information out to consumers," he said.