A law prohibiting U.S. financial institutions from processing payments to online gambling sites hasn't stopped U.S. employees from visiting sports betting sites, according to cybersecurity vendor ScanSafe.

Attempted visits to online gambling Web sites by employees of ScanSafe's U.S. customers were up 77 percent in the week between Jan. 23 and 31. The Super Bowl, the National Football League's championship game, was Sunday February 4.

ScanSafe provides a Web-blocking service to large businesses, and it examines 6 billion Web requests a month.

In October, President George Bush signed into law a measure prohibiting financial institutions from processing payments to gambling sites. The government has until mid-July to develop the processing regulations for financial institutions.

But some online gambling sites have begun telling U.S. customers that financial institutions are already distancing themselves. Last Wednesday, PokerRoom.com told U.S. customers to cash out.

"The remaining companies that process cashouts from PokerRoom.com to our players in the United States have contacted us to say that in the near future they will no longer facilitate these transactions," said a message on PokerRoom's home page. "As such we would advise all American players that have not cashed out already, to do so immediately."

The gambling provision, amended by Congress onto a ports security bill in late September, has had no impact on the number of people visiting gambling Web sites, said Dan Nadir, vice president for product strategy at ScanSafe. ScanSafe doesn't track whether those people completed bets, he said.

"We suspected [the law] wouldn't have much of an impact," Nadir said. Some gambling sites will develop alternative payment mechanisms, he said.

ScanSafe didn't provide the raw numbers of visits to gambling sites this past week, but gambling represented about 3.4 percent of the content it blocked for clients in 2006. By comparison, 15.1 percent of the blocked content was chat or instant messaging, 14.6 percent was advertising, 7.2 percent was Web mail, and 3.9 percent was pornography.

Visits to sports betting sites such as Bodog.com were common this past week, Nadir said. About 53 percent of the U.S. visits to gambling sites ScanSafe observed this past week were to sports betting sites, as opposed to casino or lottery sites. Bodog didn't immediately respond to an e-mail asking if its business has been hurt by the U.S. law.

About 84 percent of ScanSafe's customers blocked employee access to gambling sites. Companies block employees from gambling sites for a couple of reasons: because they don't trust that gambling sites are safe, and because they don't want employees playing games on company time, Nadir said.