The telcom companies know who to bill, why do they have to develop any method to fight abuse ?
Being a suspicious person, I suspect it'll be a new feature to add to the bill.
I've ran companies doing 1B+ calls a week. Any time there's some sort of complaint from a customer or vendor, we just kick it down the line and say "please verify caller ID xxx is correct". We block it, everyone moves on. No one cares. I tried a few times to get the end user to file a complaint. Vendors and customers would just get annoyed; nothing happened.
Even in cases where an AG gets involved and sends out a subpeona, I've never seen anything happen. Hell, even on DHS investigations (like where callers are pretending to be IRS agents), nothing happens.
Until the FCC starts getting serious about it, that'll remain the status quo.
(Only time I've seen things actually happen is when the request is incidental to another investigation, like "terrorism" or drugs. Why the hell they fwd us any details about the suspect beats me. All over plaintext, too.)
(And did it on simple commodity stuff, including just a $5000 SQL Server box for accounting/recording.)
Individual telecom companies know who to bill, but "the telecom companies" don't have collective knowledge except by deliberate effort.
There's no incentive to expend that effort unless it's "a new feature to add to the bill," and all it takes to make that effort worthless is one carrier who refuses to play along.
What do you do when a company has a large set of numbers on a single trunk? Do you maintain a list of authorized CID source numbers? How do you enable 3rd parties to make calls on your behalf?
Why should that be possible? If anything the disadvantages of nuisance or even scamming obviously far outweigh the benefits.
We once had a customer that set their callerID name to "DEAD" to signal that the phone number was no longer in use. People thought they were issuing threads on their outbound calls.
I see how it's a hard problem to solve in 100% of cases, but I don't see why it's not solved for most of them. Carriers have their own interconnects, pricing, and contracts. I believe 99.99% of call spam can be solved in a few months by major telcos coming up with a definition of spam callers and updating contracts to say: if you route more than N such calls within M days, and don't report who you disconnected because of it, we're disconnecting you instead. Real small telcos would have to drop misbehaving lines immediately. Fake telcos selling services only to spammers could not continue to do business.