The foolhardy actions of a few taint the fine work of so many others.

CNN reported late this Thursday afternoon that one or more journalists have been taken into custody in New York City after posing as firefighters or federal officers while covering the aftermath of Tuesday's terrorism.

These are early reports, and we must wait to hear confirmation and more details. But they are chilling to all of us who practice journalism.

Even if the reports prove untrue in this case, other journalists have fallen prey to the belief that they can masquerade their identity to get access to a story. It happened in Oklahoma City where a journalist tried to pass as a hospital worker. There are accounts of how it happened in other disasters with reporters wearing stethoscopes in hospital emergency rooms or photographers gaining access to a crime scene by pretending to be an emergency worker.

Whether apocryphal or not, these stories speak powerfully to those times when journalists are tempted to cross the line, figuratively and literally. The ethics line divides honesty and deception. It divides common sense and rash behavior. Journalists who pose as someone else during a disaster are not just unwise and unethical. They are dangerous.

Reporters and photographers fulfill unique and essential roles in our society, and that's never clearer than when we report on major disasters. Yes, we should be aggressive, but we must be smart and principled.

To pose as a law enforcement officer, firefighter, physician or emergency worker is wrong.

Doing so can endanger the welfare - maybe the lives - of others. Legitimate emergency and medical personnel can be confused or compromised. Vulnerable victims can be further harmed.

Reporting on a disaster is not like investigative reporting where some journalists have made strong cases for going undercover to reveal profound problems. Even then the threshold for justifying deception and disguise is exceptionally high, and there are consequences and credibility concerns to be seriously weighed.

Journalists who think about passing themselves off as someone else in the midst of a disaster should shut down that impulse. They should recognize the serious dangers of masquerading. They should know what harm they might cause. They should be aware of the erosion of credibility they will bring to other journalists.

And, if that logic doesn't work, rogue reporters and scamp photographers who are even thinking about passing themselves off as emergency personnel should ask themselves this question - What's wrong with law enforcement officers pretending to be journalists? Lots.

Get the picture.