unlike the others I see where you are coming at and it is also a bit of my dream. I would love to block or subscribe or throttle (give a rating that increases or decreases posts in the feed) at any level of individual, group, domain, etc. At the individual level I would like blocking to go both ways. I don't see their content and they don't see mine. I would like it to basically put us in different universes. I would like to be able to subscirbe to folks blocking lists. Im sure there is more that I have not figured out yet but I get where you are coming from.