This is something I have wondered about. We've heard the expression, "there's nothing new under the sun." I'm fairly new to quilting and the only quilts are patterns I made myself, but I bet if someone researched it, there are probably patterns out there either just like them, or close enough that someone could yell copyright infringement. But the patterns came out of my head. What then? Sure, we should not copy the patterns and give them away. Nor should we mass produce them. Barring that, I don't see it as infringement.