Also noise can be filtered even by me since they have watched two movies now. Maybe there are some other not SR people downloading the movie today as well, but how many of them downloaded movie 1 on the first day and move 2 on the second day? If I monitor the torrent swarms I can gather two crowds now and an intersection attack will reveal the people unique to both, who are almost certainly SR members. At this point I can wait to see if anybody comments on it and then if they are vendors I can try to correlate their shipping location with an IP address. The same threat risks for book ordering too unfortunately, unless you are buying the books with cash at some mom and pop book store. If you grabbing the books off Amazon don't be surprised when the FBI gets a list of everybody who ordered every book on the list of books to read, it creates a high entropy fingerprint when you match that to the timing of the posted threads and can be used to identify SR users. My biggest concern would be it narrowing DPR's crowd significantly, even if they get 100 people they detect as involved in these events they could consider surveillance on all of them if they suspect DPR is one of them.