Some years ago I wanted to create LinkedOut. It was a privacy-conscious web site, where you couldn't spill any secrets because it wouldn't take any information. You got your page, which was blank, and stayed blank. A very anti-social network.
I'm pretty sure the domain name was taken already.
On slashdot you could mark people as friends and foes. You could then assign a penalty to posts by foes (and posts by foes of foes and posts of friends of foes, I think?) so they were unlikely to meet your 'show post' point threshold and would therefor be hidden.
Great idea! What about fade-away hnstyle with a color teint? Maybe updating à gist with Val Town and referencing that gist from a css file with Stylish? Or another way js only…