I wrote this a while back. I don't know what relay it was posted to but was in the early days of nostr so might not be there. I'll post text anyway. 

nostr:nevent1qqsrxlsjx64syu9nrtw58hwrjc3lkuxeqyhpvge4hlnxs54tmjmpg0gpzamhxue69uhhyetvv9ujumn0wd68ytnzv9hxgtczyp99u5ll8dudt0dc3fd4afgks8d4ane44faddlpt7x3pmrjujcu3kqcyqqqqqqgetlpss

"1+2 I believe we could have user created filters over the newsfeed.

These filters could be shareable in the community. For example. If I'm a dog freak. I make a filter based on user follows, keywords etc. I share with everyone out there. Anyone can decide to use or not.

Maybe the filter creator can charge a few sats. Don't know. But the concept of shareable filters is a way to have a transparent 'view' of the global feed."