why can't my feed reader do that?

I love RSS. It's an info junkies wet dream. Up to the second content in a focused stream of particles beamed straight through the screen phosphor into my occipital lobe. The problem with an (un)healthy number of feeds in your reader is signal to noise. Once I got up around a hundred or so I started getting a lot of duplicate stories, and plenty of irrelevant data.

I think it was philanthropist Monty Burns who said, "I may not know art, but I know what I hate". It seems like any reasonably current feed reader is increasingly equipped with additive customization features only. That is, a saved search or smart feed style filter can be built to include news items which match certain properties, but the ability to globally exclude or ignore news items which match other properties would be just as useful. I may not always have a specific category of news in mind to include in my reading, but there are plenty of subjects I always skip over, so why waste my time?

The problem of duplicate stories is interesting because it offers an opportunity to exploit the advantages of the myriad of perspectives out there. Why can't my "all stories" or river-of-news view collect news items that share say 75% of the same outgoing URLs and group them together somehow? Take it one step further and for stories where maybe 80% or more of the links are identical highlight the differences for me so I can see unique information faster. If a big news event is covered in multiple locations maybe I want a closer look at my local media's coverage first?

Currently I've begun to remove news sources from my reader of choice because of the high dupe counts. This is absolutely the last thing I want to be doing but if the news isn't fresh and relevant then the info high just isn't as sweet ...