The Pentagon has launched a study of social networking websites and tools, part of an effort to craft policies on how the military should utilize services such as Twitter, MySpace and Facebook.
Officials said they needed to develop rules that would allow the military to take advantage of the speedy communications that social networking sites offer without exposing sensitive information or computer networks to risks.
The use of the sites could expose Defense Department networks to malicious software and create possible cyber-security problems, military officials said. Others worry that the sites could take up bandwidth that should be reserved for more urgent military uses.
The study and policy recommendations, ordered by Deputy Defense Secretary William J. Lynn, are due in late September or early October, said Bryan Whitman, a Pentagon spokesman.
While waiting for the study to be completed, Whitman said, there was no department directive to stop using the social networking sites.
"We need to take a look at both the security aspects as well as benefits of the sites," Whitman said. "So, it is a balance."
The Marines have long banned their service members from accessing Twitter, Facebook or MySpace from government computers. An order released Monday allowed some Marines, such as public affairs officers, to apply for a waiver to use the sites.
"Social networking sites have always been banned from government computers," said Lt. Craig Thomas, a Marine Corps spokesman. "Bandwidth needs to go to the operators."
Marines are allowed to access the sites from their own computers or from recreational computers provided on military bases in the U.S. and overseas.
But Marines are expected not to reveal any secrets or details from upcoming operations, Thomas said.
"What you do on your own time is your own business, as long as you keep to the Marine Corps ethos of honor, courage and commitment," he said.
Despite the Marines' ban, numerous Defense officials from other services maintain personal Facebook pages. And a number of top commanders and officers maintain public sites.
They include Mullen, chairman of the Joint Chiefs of Staff, and Army Gen. Ray Odierno, the top commander in Iraq.
On Mullen's Facebook site, his staff posts articles about the chairman and statements on current events. Mullen also uses Twitter to post comments about events in which he has participated.
Needless to say, Mullen's staff is not posting the skinny on the admiral's meetings with top Pakistani officials or his advice to President Obama.
Mullen's aides said he drafts his tweets himself, although sometimes he has his staff post them. On Tuesday, Mullen received questions on his Twitter page about whether he was going to continue to use the service.
"Obviously we need to find the right balance between security and transparency. We are working on that," Mullen wrote. "But am I still going to tweet? You bet."
Navy Capt. John Kirby, a spokesman for Mullen, said the chairman had seen the usefulness of using social media to communicate with the public.
"The genie is out of the bottle," Kirby said. "There is just such a power in it, we have to find a way to achieve this balance.
"No one wants to provide information to potential enemies," he said, "but this is a dialogue that we cannot afford not to be a part of."