This post should have ended at the bolded.
You are talking absolute tin foil hat levels of "well you could do X and Y so maybe they are doing it" Like I said, the post and your whole thoughts in this thread are based on a small amount of networking/PC hardware knowledge and the sort of paranoia you find in a VPN commercial.
Even if Netflix is using magic to determine the device I use for streaming, doesn't mean it's not receiving the data from my device in order to determine from where I stream. The actual details are not important for the argument.
Digital Identities are created by combining the following key intelligence:
Device profiling – Device identification, device health and application integrity, as well as detection of location cloaking or spoofing, (proxies, VPNs and the TOR browser).
Threat intelligence – Harnessing point-in-time detection of malware, Remote Access Trojans (RATs), automated bot attacks, session hijacking and phished accounts, then combining with global threat information such as known fraudsters and botnet participation.
Identity Data – Incorporating anonymized, non-regulated personal information such as user name, email address and more.
Behavior analytics – Defining a pattern of trusted user behavior by combining identity and transactional metadata with device identifiers, connection and location characteristics. Every transaction can be analyzed in the context of this behavior pattern and historic context globally.
Netflix is not stupid, don't act like it is.
I'll keep my tin foil hat on. Thanks for your concern. Have fun with your account sharing.
Intel Core i7 8700K | 32 GB DDR 4 PC 3200 | ROG STRIX Z370-F Gaming | Nvidia RTX 2080 Ti 11GB VRAM | Asus PG27UQ gaming on 3840 x 2160 @120 Hz GSYNC HDR| HTC Vive Pro :3
Reached PC Masterrace level.