At least here in the U.S., having a camera means that under the First Amendment, you can pretty much photograph whatever you want, whenever you want, as long as you're in a public place where there's no reasonable expectation of privacy. Of course, being able to do something doesn't always mean you should do it.
Coming to you from Sean McCrossan of When Will I Learn?, this interesting video investigates the ethical issue of shooting and sharing pictures of things like human suffering. The simple fact is that nowadays, many of us constantly have a camera in our pockets capable of instantly sharing images and videos with the world at large, which means there will be an ever-increasing number of situations in which suffering or tragedy happens in front of a multitude of lenses. I know I've personally received the random text or Snapchat before that contains such an image or video, and I remember feeling distinctly uncomfortable seeing them; after all, there was nothing I could do to help those people and being aware of something like an individual car crash certainly isn't borne of a journalistic dissemination of information. As we come across these situations more and more, we should think carefully about when we should pull our cameras and phones out and when they're better off staying put.