I meant legally they can't. They'd be sued and defeated in court. But not if Net Neutrality rules are undone.

Net neutrality rules are about source/destination of traffic, not the type. ISPs are allowed to discriminate for/against traffic based on the type of traffic and it would be terrible to prevent them from implementing those kinds of QoS rules.

If we're going to defend net neutrality, we should at least understand what we're fighting for. And it's decidedly not to allow BitTorrent traffic to make real-time protocols like VOIP unreliable. It's about not letting ISPs favor one service over its competitors. And it's about making sure that an indie developer can send traffic to internet users just as fast as Google can.

Discussions on technically-informed sites like this one should get the details of net neutrality correct.

Going with your "source/destination" definition, one Bitcoin/Signal user is source and the other is destination. They can require traffic to be exclusively between user and approved service provider, can't they?

If they prioritize traffic to/from one Bitcoin endpoint over another, that falls under net neutrality. If they prioritize non-Bitcoin traffic over all Bitcoin traffic, that doesn't.

Everything is (or slowly will be) TLS of UDP port 443. Now what type?

Deep Packet Inspection. Just run it all over HTTPS.

Net Neutrality is just about the last mile, not backbone operators. Look it up!

Last mile includes my last mile and your last mile and cannot see why blocking P2P traffic would not be part of the definition of last mile. Each user would be limited to a set of approved centralized services. No user to user routing. Only user to approved service and approved service to user.

Because net neutrality applies only to how the bits flow over the physical wiring (and radio signals) of the last mile. NOT the backbone. That's what it's about. Backbone operators can and do have peering contracts and give priority to some companies and not others.

ISPs can block all P2P traffic (bits flowing between residential IPs) and removal of Net Neutrality regulations will embolden them to do so, but it's also about the trend toward ISPs being giving the green light to do whatever they want, with eventually no regulation whatsoever.