An item of special concern is the placement of photos of forward operating bases on personal Web sites. What has officials worried is the possibility of adversaries collecting those photos and using them to plan attacks against U.S. forces.

According to Lt. Col. Brieuc Bloxam, Air Force operations security program manager, airmen have posted photos on their Web sites of personal living areas, common-use areas such as dining facilities and basketball courts, operations buildings, perimeter fences and guard shacks.

"It makes people very nervous when they come across those (on the Internet)," Bloxam said.

Maintaining operations security, Bloxam said, is one of the keys to effective force protection.

"Ultimately what's important is that OPSEC can and does save lives and increases our mission success rate," he said.

While there are no specific regulations or laws that prevent someone from posting unclassified information on a personal Web site, Bloxam said people should keep in mind the Internet's reach.

"At present, there is nothing that says I can't take personal photos with my personal camera and post them," Bloxam said. "But when you post something on the Web, you're posting to the world, and you don't control who has access to the information you're posting. You're open to threat, and you may put others at risk in the same way."

In a recent case, Bloxam said, personal photos taken by an airman and placed on a personal Web site were downloaded and placed on an anti-American site. What began as "I was here" photos for friends and family became propaganda material used by an adversary.

Air Force legal officials say a commander's right to protect his forces may supersede a person's right to post.

"I would be surprised if anybody would argue that they'd have some sort of First Amendment right to publish photos ... especially when we're in a heightened state of security," said Lt. Col. Timothy W. Murphy, chief of the command doctrine and employee law branch in the office of the Air Force Judge Advocate General.

"National security and the security of personnel are compelling reasons ... to prevent this type of speech," he said.

Murphy said if a commander determines there are legitimate security concerns, he can prohibit personnel from posting to the Internet from his location, even if that means curtailing "morale call" types of e-mail access.

"When you put security concerns together with the fact that you're using government Internet access time, it's reasonable for the U.S. military to say 'No pictures,'" he said.

While commanders may have the ultimate responsibility, Bloxam said, maintaining operations security and force protection is everyone's business.

"Security, ultimately, is everyone's responsibility," he said. "It's everyone's duty to protect themselves and the U.S. armed forces, even if that means you don't send out a photo over the Internet. That 'innocent' picture of you standing outside your dorm may provide an adversary all kinds of information."