Sorry, this slipped by me a few minutes ago but I do need to comment. In the United States of America, photography in the name of journalism, or in the name of art, or in the name of "just want to take a picture" should not be questioned by a government agent. Our courts have confirmed it's a right guaranteed under the First Amendment of the U.S. Constitution.

Except under certain very rare, very extreme circumstances such as imminent or ongoing military operations. And, writing as someone who's been on both sides of the military PAO/press relationship, a very large majority of media will recognize and respect such constraints and agree to them. But (again as someone who's walked on both sides of the fence) too often the first reaction of authority is to delay or deny because the status quo is more comfortable or because the results are unknown and possibly embarrassing. And "unknown" and "possibly embarrassing" are neither sufficient nor valid reasons to set aside the Constitution.