I'm curious where the line is drawn. What if they had a different file for every user? What if one were to setup an independent site that reported the presenc

I'm curious where the line is drawn. What if they had a different file for every user? What if one were to setup an independent site that reported the presence/absence of these files on 3rd party sites, but explicitly pointed out that the absence of the file, given the history of it's presence, meant there was a high probability that a NSL was served to a specific site, for a specific user...