I'm pretty sure getting data about # of bytes transferred on a hourly basis from Netflix's instances would be valuable to estimate # of movies viewed. Further subdividing the flow by (src, dst) IP will give a good idea about # of minutes watched per day etc.

The point is that innocent statistics about Netflix's machines gathered for routine "security" and other housekeeping efforts can lawfully give Amazon a lot of information about Netflix.

IMHO, Netflix has needlessly put themselves in a vulnerable position by moving to Amazon.