I believe there is a good case to be made that having lots of cameras in the hands of citizens makes us more, rather than less, safe. Here's how bad it has gotten: Not long ago, an Amtrak representative did an interview with local TV station Fox 5 in Washington, D.C.'s Union Station to explain that you don't need a permit to take pictures there--only to be approached by a security guard who ordered them to stop filming without a permit.Taking Photos In Public Places Is Not A Crime: Analysis (popularmechanics.com, Illustration by Rui Ricardo, courtesy Popular Mechanics)
Legally, it's pretty much always okay to take photos in a public place as long as you're not physically interfering with traffic or police operations. As Bert Krages, an attorney who specializes in photography-related legal problems and wrote Legal Handbook for Photographers, says, "The general rule is that if something is in a public place, you're entitled to photograph it." What's more, though national-security laws are often invoked when quashing photographers, Krages explains that "the Patriot Act does not restrict photography; neither does the Homeland Security Act." But this doesn't stop people from interfering with photographers, even in settings that don't seem much like national-security zones.