Earlier quoted context omitted.
Great idea - would just require some sort of moderation in that format though. I'd much rather manage my own list of domains to blacklist. A crowd sourced one I fear could be exploited and prevent me from seeing content I'd otherwise like to be able to find.
Yes, moderation is definitely necessary. For instance, easylist for adblock which has over 10000 filters is maintained by five people and is updated with input from the forum members.
any search blacklist needs to include experts exchange as a basic default (perhaps the basic list can be disabled as necessary).
its mindblowing google hasn't done this yet