Black vs. white

Clay Shirky's keen and brief note on blacklists vs. whitelists:

... the blacklist/filter out strategy: "Exclude the unwanted down to a manageable S/N" -- disadvantage being frequent pruning and increasingly baroque strategies. Advantage being preservation of serendipity.

... the whitelist/filter in strategy: "Include only the obviously relevant people and tags" -- disadvantage being loss of serendipity, advantage being great stability in set up over longer time periods.