What are the implications of copyright issues for educators?

I have to confess that I am still not so sure about what is right or what is wrong. It is a very important topic that need to have more clarification because teachers and students use the Internet and all that is available online every single day. On the article "Copyright Law and Technology", I was reflecting on how we give all the credit for a student who "created" a very detailed and illustrated work, but perhaps don't realize that half of the work was copied from the Internet and there wasn't any credit for the origin of images or sounds used in the project. I feel very fortunate that my school has a library media specialist and she is usually on top of things, but I don't remember being informed about the copyright laws and what can be used or not.
I feel a little confused about the four factors that qualify for the "fair use" of online materials. It seems a little ambiguous after checking some of the websites related to these topic. Apparently it seems that is fine to use those materials if it's for educational purposes, but then we see that there is a huge list with a lot of conditions, which we need to know to avoid future troubles.
I definitely feel the need of talking with our library media specialist to see if she can provide more training for teachers and students about this current and important issue.  As educators, we need to be aware of the copyright laws and we need to make sure we are doing the right thing and modeling to our students. We also need to make sure our students know what those laws are and we need to make sure they are accountable on this process as well.
I think the Internet provide a lot of resources and learning opportunities, but we need to be educated on how to use those tools and, at the same time, respect the content created by others.