So do legitimate services. That doesn't select for illegality, it select for how pissed people are. I bet a bank line gets a lot of irate people being called about their late mortgage payments too.
How many of the people that call in do you think calmly explain that this is a telemarkerer, and they are breaking the law, instead of being aggressive or saying "take me off your list" or "I'm on the do-not-call list" and then try to end the conversation? The assumption that both ends of the service are connected actually allows the criminal portion to continue operating for longer, as anger is likely directed at the wrong party, and possibly in an non-constructive manner.
And this all assumes people actually take time out to call the number back. How often do you go out of your way to interact with a telemarketer that doesn't have an actual person on the line for the call? My bet is the vast majority of calls are either interested parties or so enraged that understanding what they are actually upset about (and getting them to calm down enough to explain it) is actually rather rare.
Inbound call centers breathe detailed call flow scripts, metadata, abandon rates, recordings, statistics, etc. I'm quite sure they know which of their clients are legit or not.
That depends on the type of call center. I imagine an answering service for a business (which is what we're told this is) will likely be a much less defined. For a medical or legal office (which is a common use case, I imagine), the "script" will be to try to suss out if the call is actually an emergency based on client criteria (if the caller presents it as such), and either take a message or use the emergency contact info on the account and relay the info to the client. At least, that's what it's been when I've encountered them.
With more free form types of calls, identifying problem accounts might take a little longer. That said, even if it lasts a week or two before a problem account is identified and removed, who is to say that's not plenty of time for the scammers? It's not like there's only a few call answering services around. Just cycle to a new one every week or so.
Do I think services exist that cater to illegal and semi-legal activity and try to skirt the line? Yes. I just don't think we should assume that's the case here without evidence, given how trivial it would be to do this with perfectly legitimate services.
How many of the people that call in do you think calmly explain that this is a telemarkerer, and they are breaking the law, instead of being aggressive or saying "take me off your list" or "I'm on the do-not-call list" and then try to end the conversation? The assumption that both ends of the service are connected actually allows the criminal portion to continue operating for longer, as anger is likely directed at the wrong party, and possibly in an non-constructive manner.
And this all assumes people actually take time out to call the number back. How often do you go out of your way to interact with a telemarketer that doesn't have an actual person on the line for the call? My bet is the vast majority of calls are either interested parties or so enraged that understanding what they are actually upset about (and getting them to calm down enough to explain it) is actually rather rare.