Additional Web sites may be added to the Pentagon's list of blocked popular Internet destinations to make sure that the department's networks have sufficient bandwidth, officials said Wednesday.
The restricted sites are "true bandwidth hogs," said Rear Adm. Elizabeth Hight, vice director of the Defense Information Systems Agency. "They take lots and lots of bandwidth. It's a huge challenge."
Hight told a group of reporters that changes in the way the Internet is used for personal and official purposes over the last four years have forced the Defense Department to look closely at how its network is being used.
She said she did not know how much bandwidth was being taken up by military personnel accessing the sites, but the amount of information flowing over the department's network has decreased since the ban was implemented Monday. She could not say how much network usage decreased.
"Let's just think about the activity in MySpace and YouTube and other sites that involve newer technology," Hight said. "As that technology has grown and the use of that technology has grown for recreational services, I would say we're also seeing that technology grow for official uses. We just simply cannot accommodate the growth in the bandwidth demands of this newer technology for both official reasons and recreation sites."
In a May 14 directive, the department announced that all Defense computers worldwide would be blocked from accessing YouTube, MySpace and 11 other popular recreational Web sites.
Hight said that restricting certain Web sites on the department's 5 million computers ensures that there is enough bandwidth for official operations such as ordering supplies, providing logistics information and scheduling airline flights. The Web sites were selected based on the volume of data from the sites moving across department networks and not the sites' content, she said.
"We use [the network] for everything," Hight said. "Especially in areas where infrastructure is fragile, we rely specifically on military and commercial satellite bandwidth."
The directive does not prohibit Defense personnel and their families from using the Web sites on computers that are connected to the Interet by a means other than the department's network.
For two and in some cases four years, many of these sites have been blocked at military facilities in Iraq and Afghanistan, Hight said.
Military personnel can use a wide variety of services -- from e-mail and telephones -- to connect with their communities back home, Hight said. She said that the Army Knowledge Online portal can be used to share photos, videos and documents. The site currently has 1.9 million users, but limits users to 50 megabytes for e-mail storage and 50 megabytes for content storage.
Since the department's network touches the Internet in a very limited number of places, it will not be hard for the Pentagon to control the access to the sites, Hight said.
The military was not approaching a breaking point in terms of network usage, she said, but over the last six to nine months, there was an increase.
Some military organizations, such as recruiting stations, have been given waivers to access sites like YouTube and MySpace since they are used for recruiting purposes. Hight said her office looked at a variety of options for scaling back the use of the network, but since the department operates on a global level, an all-out ban was the best way to resolve the problem.
Asked whether this move would make military service less attractive, Hight noted there are alternative means to access the sites.
"I guess if you consider it your right to recreationally browse at work, it might affect your decision," she said. "But I would hope not."