I think one has to separate concepts of material, shape, etc., from what we consider capable of being 'ripped'. Right now, if i went back and re-did a couple of my older skins, i would doubtlessly be accused of ripping newer stuff. I have an old skin that looks a lot like a site theme here. There is skin at devart right now that looks like about 3 of my old ones put together. How will I fare if i ever start skinning again and bring them back?
In order for our rights to be taken seriously, we have to stop the 'lynch-mob-interruptus' that happens from time to time. When you go to the store, you see a lot of stereos that look alike. You see a lot of cameras, blenders, firearms or office supplies that share the same material, functionality, or even style.
We have to remember that not everything we make can be claimed as 'ours'. You can't copyright or an idea, or a common material like rubber, wood, or steel (though their production might be patentable). You really can't copyright a 'style', or design trends like Art Deco, Art Nouveau, Bauhaus, or Rococo would never have existed as concepts. In order for people like Frank Lloyd Wright and Walter Gropius to have been influential someone had to be influenced by them and emulate them in some way.
In short, to make people take 'protecting your rights' seriously, you have to make certain the rights you are protecting are valid. Someone, sometime, is gonna have to sue someone else. It has to happen eventually. Let's just not forget that 'imitation is the sincerest form of flattery' and people who steal your graphics should get the chair