Just to add to your clarification: Publishers do have the choice already in the exact same way that visitors have the choice to block ads. They could/have Implement(Ed) some less than perfect software that uses a bunch of heuristics to determine if the visitor/element is blocking/displaying ads then block/block the element/visitor. This assign equals rights to visitors and elements, which seems a bit off balance to me, but still they could do it already they have the technology.