Topic Proposal: Copyrights on photos

There are questions surrounding rights to images/photographs.  Photos on websites are often not owned by the site but by a photographer from a third party. Acknowledgement of the original owner of the image is often not given. Do disclaimers protect your rights for using someone else’s image without consent? There is also the grey area where if a picture of a person is taken, do they automatically own the rights to it. For example, a celebrity has his or her picture taken and it is posted in a magazine, they often have to sue for the magazine to pull the pictures.