One of the sites I follow, A Photo Editor, published a really great post for photographers today on copyright and "how to deal with infringements". I recommend taking a look (if this is an issue you've dealt with or may be dealing with in the future): http://www.aphotoeditor.com/2010/02/09/photographers-how-to-deal-with-infringements/
For the non-photographers, for the people who may not fully understand copyright- a few basic notes from me... the photographer always retains the copyright of their photos, from the moment the photo is taken until the end of time, unless otherwise stated in contract form where the copyright has been sold or transferred. An image is automatically copyrighted even without officially registering with the U.S. Copyright Office. Re-posting, printing, or any other use of someone else's photograph without prior consent (fair use, purchased stock photograph, signed contract, etc.) is illegal. In some cases compensation is required to use an image, and in some it may just be giving proper credit to the photographer and linking to their website.
Altering another photographers image is also illegal without consent. This means you are not allowed to crop an image, take out a watermark, change the coloring, add to it, take away from it, etc. etc. etc. without the photographers consent. And if you print out someone else's photograph at home or at a photo lab, even if it's of you, without proper consent, you are not only being an asshole but breaking the law. Just beacause your likeness may be in an image, it does not mean you have any rights to the image.
I originally was just going to post the above link because I thought it may be useful to other photographers. Then I got on a rant, because I have recently been dealing with copyright issues, and I've heard from alot of other photographers recently who have also been dealing with this issue. With the internet comes good and bad... artists may have more exposure due to the internet, but copright infringement is extremely prevelent these days and is not only hard to track, but hard to prevent. Most people do not understand that it's not just bad curtesy, but also a legit legal issue.
Back in October, I posted a few sentecnes referring to another post on this issue, if you missed it and want to read more, go here.
