Jenna Jameson now has a 9-to-5 job. Fully one quarter of employees who use the Internet visit porn sites during the workday, according to October figures from Nielsen Online; that’s up from 23 percent a year ago. And hits are highest during office hours than at any other time of day, reports M. J. McMahon, publisher of AVN Online magazine, which tracks the adult video industry.

What’s driving workers to get their kicks on company time? It’s one more thing we can pin on the slow economy. “People are looking for an escape,” says Steve Hirsch, CEO of Vivid Entertainment Group, an adult online-video provider. And rightly or wrongly, they think their bosses are too busy to notice, says Dawn Adams, CEO of Wisconsin consulting firm HResults.

“Managers are dealing with so many issues right now,” she says, “that sometimes people are able to hide out and no one knows what they’re doing.” AVN’s McMahon attributes the rise in workplace porn to the proliferation of free Web sites, such as xtube.com, that allow users to quickly log on and off.

But a larger factor is the evolving sense—not universally shared—that porn is no big deal. “You’re looking at a younger consumer who has grown up with pornography being out there in the pop culture,” McMahon says.

Some can’t seem to stay away from it. Earlier this year, nine Washington, D.C., city employees—including at least one from Child and Family Services—were fired for viewing porn sites thousands of times while on the job. The worst offender reportedly logged an average of one hit every 2.5 minutes.

The threat to companies isn’t just the lost hours of productivity and the risk of sexual-harassment lawsuits. Adult sites also expose computers to viruses, adware and spyware—though such ills can serve as smoking guns. At her last job, Adams fired an executive for spending hours a day on adult sites. “His computer was always crashing,” she says. “That’s how we found out.”