[kbuck]

The U.S. also has a do-not-call registry that you get fined for violating (donotcall.gov). The problem is that they don't know who to fine, because it's really easy to spoof caller ID and the businesses aren't dumb enough to identify themselves.

[tripzilch]

How can those businesses try to sell you something without identifying themselves?

Also, there must be some weird political or legal reason why they can't (or won't) get the identity from the phone companies. It can't be a technical reason, because they're already capable of tapping everything, and the phone companies are already in full cooperation with that, even developing and providing specific technical interfaces for law enforcement.

And, maybe someone can tell me if this is actually possible (as opposed to a "CSI" type exaggeration): In many police series you see them requesting full cell-phone logs of all incoming and outgoing calls to a certain phone in the past few weeks or so.

In case that's realistic, I certainly hope that it can't be foiled by something as simple as spoofing the caller ID? Because, you know, that'd make it really easy to frame someone.

[kbuck]

I haven't seen or heard one of these calls actually play out, but they might not even be trying to sell something - they could just be scammers out to steal credit card information. (I get one all the time that's a prerecorded message from "Rachel from Cardholder Services")

I'm sure telephone companies could technically stop them if they really wanted to, but telephone companies make a profit from these people. What incentive do they have to stop them? Same with text message spam. If they tracked it (which they surely collect enough money per message to do), they could easily notice one number sending a hundred spam texts and stop it before it sends tens of thousands of them. They don't, though, because each of these messages means anywhere from another 5 to 25 cents in their pocket. Most people don't even contest getting charged for receiving spam texts, because who's going to argue over a quarter?

The biggest issue seems to be that all of this data is ephemeral - even if they had a "more powerful" caller ID (which I believe 911 dispatchers do), you would have to catch them in the act and personally have access to check where the other end of the call is terminating, and you'd have to do it before they hung up. For IP calls, I think it's unlikely they would even be able to fully trace it.

[tripzilch]

> What incentive do they have to stop them?

That it's illegal? (the ones that are)

[kbuck]

It's not illegal for the telephone company to not try stopping them.