Nielsen Online said its October figures show the percentage of employees browsing online porn sites in the workplace has increased from 23 percent a year ago to 25 percent, Newsweek reports in its Dec. 8 issue.

The reasons for such an apparent increase in porn browsing in the U.S. workplace could vary from different social ideals to overworked managers, experts say.

AVN Online magazine publisher M.J. McMahon, whose group follows the adult video world, has suggested porn is commonplace to many young U.S. residents.

"You're looking at a younger consumer who has grown up with pornography being out there in the pop culture," McMahon offered.

Dawn Adams of the Wisconsin consulting firm, HResults, said workplace managers are simply too busy to keep a close eye on their employees all day long.

"Managers are dealing with so many issues right now," she told Newsweek, "that sometimes people are able to hide out and no one knows what they're doing."