If it does not belong to you, it is not yours. If you take it, you are stealing. A simple, moral idea that is often betrayed. Copyright laws protect an artist's work. Writers need to protect their words; photographers need to protect their images. The laws may appear to be complex, but the rules are basic.
The U.S. Constitution and the Federal Copyright Act protect the original works of "authors." The "author" is the copyright owner, and has exclusive rights to make copies of his work, create other works based on the original, display or perform the work in public and make copies of the work for sale, lease, rent or lending.
The "author" is the person who took the photo; the owner is the person who snapped the shutter. If a photographer takes a photo of you, that photographer owns the copyright of the photo. A photographer who is employed by a studio--or even newspapers--is not usually considered the "author," the employer is.
Registration is not required for copyright protection. There is a $20 fee as of 2009 and forms that need to be filled out in order to register a copyright, which makes it a pricey and time-consuming for a photographer to register thousands of photos. Instead, a photographer may chose to register just his portfolio photographs.
Copyright infringement, the unauthorized use of copyrighted work, includes photos on the Web, as well as in print. Even if you do not see a copyright symbol, you should suspect that it probably is protected and not available for public use. It is recommended that photographers use copyright watermarks or include a copyright symbol to protect their images that appear on the Web.
An artist's work is their own. There are more than a half-million images of the Golden Gate Bridge on Flickr, but each is unique to a specific photographer. It is possible for someone to try to recreate a more stylized or studio shot that is truly an original concept, but the infringement can be challenged, and it would be up to a court to decide on the degree of similarity between the works.