In fact, when nomo robo (www.nomorobo.com) came up with a pretty good solution (they won an FCC robo blocking contest ), the phone companies lobbied congress to shut it down. No only were they not helping, they were blocking progress from others.
In order to combat this, all tier-1 carriers now have ASR (answer ratio) and ACD (average call duration) minimums. In addition, if you have more than ~10% of your calls less than 6 seconds, you get an ADDITIONAL 1-2 cent per call surcharge. That's a lot of money given that my average cost of long distance is .17 cents ($0.0017) per minute.
It's the second tier carriers that is "blending" this traffic with good traffic in order to get the minimums then charge the telemarketers much higher costs per minute.
Conversely there are a number of large, more ethical SIP providers who will cut you off if your outbound traffic consistently falls into the same pattern with low ACD. "No dialer traffic" is turning up in Terms of Service agreements with greater frequency.
It depends on which provider, but the dialer penalties usually aren't that harsh. Regardless, everyone's cautious. And they'll mix right to the limit. Put on restrictions on how many times a number can call? They'll switch up numbers and keep the mix perfect.
It creates a huge opportunity. If the FCC was serious, they'd just start cracking down and push liability on down the line. Then no one would want to take the risk. It's high volume, so without huge deposits and guarantees, no one would touch it.
There is also the other side, do they lose any money from spam calls? If they don't or it's negligible, they aren't going to be open to spending money to block them.
I guess the article above describes the phone companies are working on it.
I'm not sure how important lists are.
You are correct in that I think they (telcos) lost. I believe the founder of nomrobo had to testify before congress. He emailed a petition to users a year or two ago, asking us to write supportive testimonials. I think he presented the testimonials to congress and won.