Watch where you point that camera

If you pull out a camera on a New Jersey train, you will have company - law enforcement company. If you size up a shot on the New York subway, you'll probably be questioned by security and told to keep the lens cap tightly on. Even if you plan to snap some innocuous bank building from a public sidewalk, you might find guards telling you it's not allowed.

"Is photography becoming illegal in the United States?" asks Jim McGee, in a column for the online photo magazine Vivid Light Photography.

Anecdotal evidence suggests that heightened sensitivities over security in the wake of 9/11 have put a crimp in photographers' freedom to shoot in public, even if the laws remain largely unchanged. News that Al Qaeda operatives canvassed targets with cameras has made taking shots of federal buildings, bridges, power plants, and the like seem less innocent.

Last year, after the Madrid train bombing, New York City's Metropolitan Transportation Authority proposed a ban on photography on its subways and buses (New Jersey already had a ban in place). Public protest was such that now, more than a year later, the proposal has stalled.

But "just because it's not law yet, doesn't mean there aren't people trying to enforce it," says Alicia Wagner Calzada, vice president of the National Press Photographers Association (NPPA).

Part of the problem, she suggests, is police officers and security guards who are uneducated about the law.

The USA Patriot Act, with its broad definition of "suspicious activity," has cracked the door wider to individual interpretation.

Ms. Calzada offers the example of a small-town photojournalist in Victoria, Texas, who was taking shots of potholes for a newspaper story last year when a police officer drove by several times. Finally, the officer stopped and questioned him and, even after running an ID check, bluntly declared the photographer's actions suspicious and intimated he'd be keeping an eye on him, the photographer recalls.

In most cases where photojournalists have been accused of shooting illegally and detained, they have been released without charge, Calzada says.

If security is sometimes overzealous, the rules themselves can also be vague and ad hoc. Overlapping law enforcement agencies, new restrictions imposed by local municipalities, and beefed-up security have all added to the murkiness.

"TSA [Transportation Security Administration] and [the Department of] Homeland Security have put a whole 'nother layer of protection and concern and a level of bureaucracy to what journalists used to see as free rein," says Kenneth Irby, visual journalism group leader at the Poynter Institute in St. Petersburg, Fla.

In general, photojournalists have no more rights than ordinary citizens to take pictures.

If you're standing on public property, you can shoot anything the naked eye can see, explains Ken Kobre, professor of photojournalism at San Francisco State University and author of one of the seminal textbooks on the subject.

What you can't do, he says, is use a telephoto lens and take shots through office windows or into private residences, where people would have a "reasonable expectation of privacy." That would be like eavesdropping or surreptitiously taping someone, he says.

But if a story is newsworthy and in the public interest, then taking photos even on private property is usually permissible, he adds.

Photographing the outside of buildings - schools, hospitals, and even government buildings - is also legal. It's when you go inside that you need permission.

In most cases, Professor Kobre says, people are evicted for trespassing rather than invasion of privacy.

What surprises him, though, is the logic behind preventing people from taking pictures of building facades. "I haven't heard of an example where it makes any sense to stop anyone," he says, "because, almost in every case, you can walk a block away and use a longer lens."

Whether the logic is compelling or not, law enforcement has knocked heads with photojournalists for decades. The apparent tightening of access during recent years is less a function of more run-ins with the authorities, says Mr. Irby, who has seen no evidence of that, than the media's increased coverage of those encounters.

"In the past, when photographers were detained and even arrested, the news organizations would likely contact the commanding officer at the precinct ... and everything would be settled," he says. Now, in a time of heavy national security and greater public interest in press freedom, "those stories become stories."

Despite that higher profile, most incidents, Irby adds, are connected less to the war on terrorism than to the standard traffic accident or homicide scene.

Other factors play a role as well. During the past 10 to 15 years, police and even bystanders have become less tolerant of photojournalists, Kobre says. "The public really reached its apex of being fed up" with paparazzi after Princess Diana's death, he says. And the distinction between paparazzi and mainstream journalists is disappearing as celebrity journalism seeps into all areas of the media. [Editor's note: The original version misattributed Kobre's quote.]

The bigger issue Kobre sees is privacy and the ease with which individuals can take clandestine photos with cellphone cameras.

"Before, you had to go to some trouble to hide the camera," he says. "Now you look like you're making a telephone call and boom! You've got [an embarrassing] photograph of someone." If that ends up on a blog, can the subject sue? Kobre asks.

In terms of the general public, he says, this "is going to explode as a problem."