The Web can be a great waste of time at work.

From catching up on the latest weird videos to planning a wedding, millions of people use the Internet every day. But much of that surfing is done from a cubicle, leading to hours of questionable productivity and strained resources.

In response, workplace Internet policies are getting stricter.

Companies are starting to ban Web access, block instant messaging services to squash discreet conversations among chatty co-workers and prohibit employees from watching sporting events on their computers.

“If you’re watching video, you’re probably not working,” said Vimal Solanki, director of product marketing at McAfee Inc., a software vendor whose products to block Web access are selling briskly.

In fact, the Web has become so addictive that 54 percent of men said they would rather give up their morning coffee than lose their personal Internet fix at work, according to a new survey. And 47 percent of women said they would do the same.

“The Internet has become the modern-day equivalent of the phone,” said Richard Chaifetz, chief executive officer of ComPsych, a Chicago-based provider of employee assistance programs. “The difference is the phone is more obvious; you know when someone is talking. But the Internet is more stealth. It can be hard to tell when someone is online.”

This is where the new restrictions come into play. Employers are moving to restrict viewing of video content, which can use bandwidth and be a drain on resources. Other concerns include guarding against legal threats, such as sexual harassment, and preventing malicious software from disabling a corporate network.

Some employers are requiring workers to fill out forms before gaining Web access, justifying their need to be online. Others restrict use of e-mail altogether.

And employers are getting serious about rules. An employee for the New York City education department recently was fired for using the Web to read online news reports and visit travel sites while at work; he had been warned to stop.

That is not an isolated case. According to a survey conducted in 2005 by the ePolicy Institute and the American Management Assn., 26 percent of employers have fired workers for misusing the Internet. A total of 526 companies responded to the survey.

The survey also found 65 percent of companies use software to limit or block Internet access, a 27 percent increase since the survey was last conducted in 2001.

“I’m surprised it’s not 100 percent,” said Nancy Flynn, executive director of ePolicy, a consulting firm that works with companies to reduce Internet risks. “I don’t think it’s extreme to enforce that an employee’s computer use is for the company, not personal business.”

The biggest reason why, Flynn said, is legal liability.

“The courts make no distinction between electronic messages and paper messages,” she said. “If your organization is involved in a lawsuit, you can take it to the bank that your employees’ e-mail messages will be subpoenaed and their history of Internet surfing could be looked at, too.”

She added that inappropriate Web surfing, such as a worker who visits a pornographic site and positions the computer screen so that other workers see the images, could trigger a sexual harassment suit.

Another survey found that 16 percent of men who access the Web from work had visited a porn site, while only 8 percent of women had done so.

During the past year, sales of hardware and software products to restrict Web access have been increasing, said McAfee’s Solanki. “Videos, MP3 files and other such content is choking up Internet resources and not allowing the networks to work well.”