So you can replace advertisements for art that takes you to a web site where you can buy their art? Hijacking ad space on the client side side-steps all the leg

So you can replace advertisements for art that takes you to a web site where you can buy their art? Hijacking ad space on the client side side-steps all the legal issues I've seen with this happening at the ISP level. What is interesting to me is that the people who download this plugin are self selecting themselves to the artists as people that like/enjoy art. Who is going to be the first to make the "organic" web browser that uses this same thing to replace existing ads with relevant organic only labels?