By Rita Zeidner, May 2007

Social networking sites such as YouTube and MySpace are now off-limits to civilian and military employees of the Department of Defense (DOD).

Excessive use of such sites, a DOD spokesman told SHRM Online, is "eating up" the military's information technology resources.

These days, it's not unusual for employers to block employee Internet access. In fact, more than three-quarters of chief information officers polled recently by Robert Half International said their companies have installed content-filtering or blocking software or have instituted policies that detail acceptable web browsing, or both.

DOD maintains that the use of blocking software is based strictly on the need to reserve Internet resources and is not aimed at restricting employees' free speech rights, as some critics have asserted.

"This does not relate to content in any way," he said.

Employees who now attempt to access such sites using a DOD Internet connection will simply get a message indicating that access is denied.

Many employers are increasingly aware of the strain that multimedia Internet applications can place on a network. Some report a noticeable drag during March Madness or even during the Christmas holiday season, when many workers are shopping online or passing along increasingly high-tech greetings and jokes that can slow the flow of legitimate information.

Many employers also use the kind of blocking software DOD has installed to prevent workers from accessing pornography or other materials that might offend some employees and lead to a sexual harassment lawsuit.