This Google Video sums up the philosophy of Circles perfectly in the last line: “Aunt Ruth doesn’t need to know.” Therein lies my problem with the motivation of circles: It’s preventing people from seeing things they shouldn’t, not necessarily showing them things they’re interested in, and not providing them any way to categorize incoming posts (i.e., streams). That’s where circles really fall down, on the streams side. I can put you as a poster in any circle–more than one circle–but there’s no real link between how I categorize you and what you’re actually going to talk about.
Reposted from Google+.