I would think Netflix would be protective of their content and would likely have monitoring to detect mass downloading. The adversarial nature of one person trying to do something and other people trying to detect and stop them is interesting to me. I find JSOR's account of their monitoring, detection, and attempted blocking of Aaron Swartz's downloading of academic papers (not just metadata like this post), and the cat and mouse game that followed to be very interesting. https://docs.jstor.org/summary.html
And the perspective from the other side: the authors of this paper, whether they were concerned with being detected by Netflix and possibly blocked or even banned from Netflix for life, and maybe took action to avoid that such as using multiple accounts or VPNs.