Where and when you can shoot
When it comes to the legality of what you can shoot, and where you can shoot from, it all boils down to this: as long as you are on public property and not interferring with or restricting traffic, you can photograph anything or anyone, anywhere, at any time, without permission, permit, or release. Even if the person or object is on private property, you can photograph it, as long as you are on public lands. Paparazzi do it on a daily basis. In fact, it's the legal basis of their entire profession.

There is no law in the U.S. that prevents you from photographing bridges, airports, etc. Yet in the interest of swelling their heads, puffing out their chests, and generally making themselves feel much more important than they actually are, many "officials" will trot out these nonexistent laws as an excuse to harass photographers.

One of the biggest areas of confusion is the ban on photographing federal buildings. There is no such ban. There are certain areas of military and nuclear facilities that cannot be photographed, but these areas are inside the perimeter of the facilities. And any property owner has the right to restrict the activities that take place on their property. But as long as you remain outside of the property, on public land, you're free to photograph pretty much whatever you like.

The confrontation
In the event you have a confrontation with law enforcement or security, knowledge is your best defense. The FAQs on the government's copyright Web site, and Bert Krages' "The Photographer's Right" are excellent resources. Bert just happens to be an attorney specializing in photography, copyright, and patent law. It may even be in your best interest to keep copies of pertinent information in your camera case. But first, be sure you are in the right.

Next, be civil, polite, and cooperative to the extent the law requires. No one can legally confiscate your equipment without a court order.

I'll repeat myself in case you missed it: be civil and polite. No matter what your position and what you need to accomplish, there's no need to scream and yell. If you are calm and remain calm, you'll be far more credible than if you appear completely nuts. And, the people you're interacting with will be far more inclined to like you, not fear you, and not over-react.

Make sure to get complete information on every person involved, including their name, rank, where they are assigned, and their supervisor's name. You are legally entitled to this information in any situation where you have dealings with law enforcement authorities. Ask politely but firmly.

Immediately following the incident, write down a complete and factual account of everything that occurred and everything that was said. Be sure to include pertinent things like body language, tone of voice, sarcasm, and how you felt. Also include key reference data like the time, date, location, people around, names of any witnesses you may recall, and so forth. You may then want to contact your attorney, depending on how the situation unfolded.