Just as businesses are becoming more transparent, the personal lives of their employees are also increasingly open to scrutiny. A wide range of new technologies allows companies to monitor individuals’ Internet activity and calling patterns at work. Some companies even use video cameras to observe activities.

For employers, this means they can be more aware of what employees are doing on company time. The benefits of monitoring employee communications include lower costs, higher productivity, and the prevention of improper activity that could hurt the company. The drawbacks include the costs of software, a weakening of employee morale, and perhaps an increase in turnover.

There is plenty of data to back up the perception that many employees use business hours to make personal calls, send e-mails to friends, and visit Web sites that have nothing to do with their jobs.

According to research firm ComScore Networks, 59 percent of all Web purchases in the U.S. in 2001 were made from the workplace. Half of employees spend at least 30 minutes a day using the Internet for personal reasons, whether they’re shopping on eBay or checking their stock portfolios. And a study by the Gartner Group discovered that Internet activity by employees costs U.S. companies $54 billion in lost productivity.

When you factor in the high cost of employee theft of everything from paper clips to personal computers to company secrets, and the risk of a sexual harassment lawsuit if employees e-mail pornographic material to each other, it’s no wonder that many businesses are keeping a close watch on what their employees are doing.

Four out of five American companies monitor their workers by checking their e-mail, Internet, or telephone connections, or by videotaping them at work, according to a survey by the American Management Association. This was a 35 percent increase in monitoring among companies that participated in the study four years earlier.

If your company has 1,000 employees, and only half of them spend only half an hour a day on the Web for personal reasons, you are losing 250 hours of productivity per day. At 250 workdays per year, that’s 62,500 hours. Divide that number by a 40-hour workweek, and you end up with 1,562.5 weeks per year.

Now divide that number by 52 weeks, and the quotient of 30 stands for the number of full-time employees whom you...