And what on earth is a "discernible subject"? If you mean people, they clearly have the "right." Rights are not given or taken by photographers; rights are a matter of law. If by "right" you mean "courtesy" that's another story. Some photographers are courteous, others aren't depending on circumstances. The same is true of everyone else as well. If you absolutely don't want to be photographed in a public place, you have the right to avoid that place.
