Public Domain Pictures
Obtaining public domain pictures is easier than you might think. However, before you help yourself to other people's photos, there are a few rules you should be aware of.
What are Public Domain Pictures?
Not all
photos posted on the Internet are in the public domain. Just because an image is accessible on the web doesn't make it free to use in any way you choose.
Copyright
Photographs are protected by copyright; unauthorized use is illegal. The majority of the images in the public domain are free of copyright restrictions. However, it is vital that you examine the terms and conditions of use before using a picture that you didn't take. In most cases, all that's required to use an image is the addition of a credit line. By crediting the source, you can avoid infringement issues.
Rights Managed
Photos that are "rights managed" can only be used in a limited capacity. In addition, an ongoing fee will be assessed each time you post the image. The fee is dependent on how and where you want use the image, and the duration of use. To avoid costly fees, it's best to use a restriction-free public
domain picture.
How to Determine if a Photo is in the Public Domain
Since copyright notices are no longer required in the United States, determining whether a photo is in the public domain can be tricky. It is important that you never assume that lack of notice means a photo isn't protected by copyright. You can determine whether a picture is in the public domain by the following criteria:
Government Photos
Any image taken and published by the U.S. government is not protected by copyright. Therefore, a good source of public domain photos is the federal government.
Lack of Copyright
If an image was published prior to 1989, it required a copyright notice.
All photos published after 1989 are generally restriction free and available for use by the public for free unless otherwise stated.
Expiration of Copyright
After a set amount of time copyrights expire. Once that happens, the image enters the public domain and individuals are allowed to use it freely. To determine the expiration date of a photo's copyright you need to know when the picture was published. Upon obtaining this information, you can determine which copyright term applies.
Specific Public Domain Photo Sites
Some photographers encourage the use of their images, so they post them on public
websites. There are hundreds of public domain photo sites on the Internet featuring thousands of restriction free images. These sites typically have a highly visible written statement posted on the main page stating that the works published are in the public domain.
The one caveat with public domain photo sites involves pictures that feature identifiable individuals. If you want to use a photo which includes a recognizable person, you must obtain permission first. If you don't, you could be charged with violating privacy rights. Individuals have a legal right to privacy, and the use of their likeness for commercial advertising typically requires a written consent agreement.
SOURCE:
http://photography.lovetoknow.com/Public_Domain_Pictures