They could easily fine the carrier that is interconnecting the robo callers. The telecom lobby doesn’t want to fix the issues since they make money from robo callers and also selling services to block the robo callers.

The souce may very well be outdide the US, with no sure way to spot spam. I'm all against imperial hegemony and all, but i doubt the UN eould care if they sent some stealth bombers after the spamers.

International carriers still interconnect with a us carrier to deliver the calls. Spam is really easy to detect. Short call durations and lots of different call to numbers.

Even just giving origin information would help, if the local end of the interconnect ensured calls show the international dial-code as a minimum then that would help; instead we get (in UK) international calls (India, primarily) with caller ID showing a local number (sometimes your own number, I think) ... the interconnect certainly shouldn't be facilitating that.

That's easier said than done.

SS7 its the primarily utilized protocol stack nowadays. The PTSN (Public Telephone Switching Network) and the Internet have been combined for a while now.

The problematic part of SS7 is it allows for setting arbitrary unauthenticated origination info in the rough equivalent of a "From" field in the initiation process.

There are attempts ongoing to attempt to implement a "Web of Trust" layer a la TLS on in front of the preexisting telephony infrastructure in the form of STIR/SHAKEN, but it'll have some of the same warts that current "Web of Trust" implementations now currently suffer.

It was my understanding that in PSTN at country-level boundaries the operators choose to forward calls, and do billing and such recording: at that point they decide whether to put the call to the local country network or not. If the call has meta-data as if its come from the local country then they could drop the call request, but they establish the voice call [because call senders pay more than call receivers, presumably].

Is that incorrect?

https://en.m.wikipedia.org/wiki/Signalling_System_No._7

Telecoms aren't responsible for who uses their service, or what they do on it—thats why they are classified as a utility.

Sure, but there could be DMCA-style “you’re not liable, unless we point it out to you and you don’t act on the information” mechanisms.

It feels super reasonable to ask for telecoms to blacklist stuff after complaints

They are currently empowered to do that already. You just have to give explicit consent.

Can we get that same logic applied to data transmissions occurring on the same circuits then?

Define "illegal call" and how you'd classify that before the call happens. You'll see why it's not done.

Yoy don't need to classify it before it happens. You classify it after it happens.

The context was:

> fine the telecoms for allowing the illegal calls

You can certainly fine companies for making illegal calls. But you can't easily fine telcos for allowing them. That requires you to know the call is going to be illegal.