the magic word here is “HTTPS”. Prior to encrypted downloads being the norm, it was trivial for your ISP (and presumably, the feds) to see what sites you were visiting and what you downloaded from them. With HTTPS, at best it’s possible to know what site you’re communicating with and how much data you’ve sent to and received from them, but not what the data actually is. (Unless of course the site’s logs get seized, which could contain records of which files were requested by which IP addresses)

my favorite was the Madonna song that was just Madonna saying “What the fuck do you think you’re doing?” over and over again for three minutes, and then someone made a dance remix of it and uploaded it again