> Strangely enough, it can identify users across sites (even without knowing your identity) - say Reddit and Hacker News.
I think a larger demonstration could make for a very meaningful "Show HN" with hopefully a large impact on privacy consciousness.
I'm sure some of us expected this, but to have it demonstrated by a single person in a casual "Oh, it could do this as well, but I don't have it turned on for ethical reasons" manner is quite effective.
Maybe it will raise awareness that "big data" isn't just trying to correlate cat-pictures one posts on their communication medium to cat food advertising, but everything you write anywhere on the Internet, even on different media under different (or no) accounts, into permanent and guarded profiles with no recourse of opting-out of the machine, effectively rendering informal discourse over the Internet dead.