The answers to this popular question were somewhat controversial, but many including @dan-romik whose answer was highly upvoted mentioned that recording a video is a violation of personal privacy and in the US, Family Educational Rights and Privacy Act.
I neither can speak for the OP of that question nor approve his/approach, but the strong stance regarding personal privacy puzzled me. The mentioned question says
We have a youtube channel in which students regularly explain their achievements.
Point 1: Can the reports of a PhD student recorded in video format?
- A PhD student normally delivers reports of progress to the supervisor. This report can be in verbal or written form.
- I do not see any problem (including privacy) if the supervisor asks the PhD student to deliver his/her report in video format.
- Alternatively, the supervisor may ask the PhD student to deliver a public lecture in the department. Since it is a public lecture, anyone can record the presentation unless otherwise strictly stated by the organiser.
- Similarly, the progress could be presented at a conference. Many conferences record the presentations.
Point 2: Can a supervisor share the presentations of a PhD student?
A research report is not intended for the supervisor's eyes only. An educator cannot share the exam sheet of a student (according to FERP), but the story is completely different for a research report. The supervisor can/will directly use that report to report to the funding agency who funded the PhD project in the first place.
The progress report is not only the progress of PhD student but the work done in the supervisor's group. Therefore, it is not odd for the supervisor to post the report publicly (e.g., the university website, researchgate, etc).
Conclusion: Is video different from writing?
For centuries, academics presented their works in both oral and writing formats. Thanks to Johannes Gutenberg, writings are well recorded for centuries. However, video recording of the presentations is new, a few decades of recording, and one decade of sharing.
As a straightforward question, can someone refuse to appear in any recording because of personal privacy? This can apply to the PhD defence meeting too, as some universities record its video to be stored along with the written dissertation.