The value derived from this post is not it's "recentness" but to make aware of a practice by fb to the users of this site, specially in the light of fb importance on privacy matters and global politics in recent years

I didn’t know it, but if you have a link to previous HN discussions about it, that would be nice to have here.

Is the difference now that the tracking metadata used to be set at upload time, and now it's set at download time? Presumably, if you set it at download time, you can not only track the uploader but also the downloader.