Hi Tom (and forum),
Thanks very much for posting the DoH youtube video.
One thought/question: One possibility for controlling access would be to blacklist port 443 for known DoH providers, or just block the IP altogether. Of course, this might cause problems if that host also serves useful websites (google.com, etc) if the same server is running a high-traffic website. Thoughts on whether this strategy would work in practice?
-Greg
Yes, it would break things running on those sites, but you could do it.