Hey--
Copyright is a legal protection of your work. It doesn't stop anyone from doing anything; it just gives you legal recourse if someone takes one of your photos and tries to profit from it.

Copyright is almost impossible to enforce in digital media -- think about how easy it is to download mp3s, or right click on any of our photos and Save As.

But that's only for individuals -- companies and organizations can be sued for payment if they try to use your work without permission. You'd have to catch them at it, of course.

Here's a lot more information.