Comment Re:This is what I don't get... (Score 1) 171
These days most calls are just VoIP data, phone companies don't really have the infrastructure to track incoming calls; I mean sure they know that a call came in and how long it was. But they only know it came from IP x.x.x.x.x they don't know where it came from before that, not really. If the packets are properly formatted they just connect them to their destination. Similar to how an email server has to rely on self-reporting of e-mail headers to verify authenticity, phone companies are trusting that information being sent to them from an outside carrier is accurate.
There's also a lot of reasons that a caller ID wouldn't match a phone number being dialed, a prime example is for a call center to have a central call in number; but each phone has it's own extension if you need to directly reach a particular person.
Now with some regulation it would be possible to require a company verify they own the number they're self reporting on caller ID, and that would help cut down on/block a lot of robocalls.