You're the only one out of 100 that visits HN, or who's use matches a particular timezone, or who has the use pattern that [anti-]correlates with your work pattern, or ...
So the HN operator sees someone using this browser, with this timezone. Then I go to some other site. Let's pretend that site's operator and HN's are identical. How will they know that I'm the same guy who went to HN? How does he know there aren't two people who use the browser in the same timezone (and the other one doesn't go to HN)?
My brain is a bit slow today:
> You're the only one out of 100 that visits HN
So the HN operator sees someone using this browser, with this timezone. Then I go to some other site. Let's pretend that site's operator and HN's are identical. How will they know that I'm the same guy who went to HN? How does he know there aren't two people who use the browser in the same timezone (and the other one doesn't go to HN)?