You're confusing eavesdropping law with tracking in general. (You're probably thinking of the one party vs two party consent issue: https://en.wikipedia.org/wi

You're confusing eavesdropping law with tracking in general. (You're probably thinking of the one party vs two party consent issue: https://en.wikipedia.org/wiki/Telephone_recording_laws https://en.wikipedia.org/wiki/Telephone_recording_laws) If I were to somehow create a Game of Thrones video file that "phones home", yes that would need to be disclosed. If I want to add an invisible watermark to a video file and note who got the video with that watermark, that is legal.