Digg = NYTimes, SlashDot = Washington Post?

Here is an interesting graph that implies Digg and SlashDot not only have similar traffic, as was implied in several articles, but this Alexa data implies that Digg and the NYT are tracking each other uncannily closely, and SlashDot and The Washington Post are doing the same. Strange how closely the lines track each other. I threw in the red Netscape line for good measure, which shows a muted reflection of the same peaks and valleys.