> If Reddit forces this, I assume browser extensions are the next step that they can’t mitigate. If the browser needs to play it, it can be ripped.

I assume from a legal point of view that is a-ok. They can't do anything about it therefore they can't be expected to do anything about it.

Can they enforce DRM on the videos through EME?

Maybe, depends on the amount of effort they want to put into it. Right now, if I recall, they're just dumping the uploaded content into an S3 bucket and serving it back out (reddit-uploaded-media.s3-accelerate.amazonaws.com).

I was pretty sure that they at least transcode it currently. At that point encrypting isn't a big deal.