Digital Watermarks for video conferneces

Could each video stream be provided with an individual digital watermark for each participant?

This watermark could then be recognized by video platforms such as YouTube and uploading could be prevented.
At the same time, the person responsible for an illegal upload could be determined.

The background is: video conferences are illegally recorded and uploaded to video platforms by students. Often they are manipulated in order to despise the teacher.

It would give the teachers a little more security so that they can continue to offer video lessons.

I think that would be a good USP for Jitsi.