I took a class in copyright law during my legal career. There are different restrictions for different things and different expiration dates for copyrights. For quilting it is very long time. The key word regarding art/quilting is COPY. Also if a designer wants to pursue legal action, he/she must have the copyright actually registered. Most homegrown quilters do not. Putting the copyright symbol is not enough. Also techniques i.e. paper piecing, fusible applique, binding, etc. cannot be copyrighted, only the written word. Designers have no defense by making statements such as, you can only make one, you cannot give this away, etc. etc. there are some fabric companies you dont want to take a chance with if you are planning to sell items as they have the resources to pursue legal action and they do! I.e. Disney and national sports teams. I "heard second hand" that if someone walks into Disneyland with a homemade item made with a character fabric, they will confiscate it. Notice that in Joanns their chacter fabric is in a separate section. Instead of asking legal type questions here try google for more accurate info. Google quilt copyright law and you will get several choices. This one is pretty straight forward.
http://www.tabberone.com/Trademarks/...Quilting.shtml
The other thing is about the moral factor. When I teach quilt classes from a pattern, I think it is only fair to the designer to have class members buy the pattern. I refuse to COPY a pattern or change it with other wording and hand it out. I must say though that I think the price of hand scribbled 2 xeroxed pages has gotten out of hand!