I must receive at least 3 to 4 spam calls a day on my land line. Am on national do not call list, and call blocking here on sonic. Nothing seems to stop these calls, very frustrating, now it's starting on my cell phone......
To be fair, I'm not sure there's much Sonic, or any other company can do here.
If the spam calls you get are anything like the ones I get on my mobile phone, these are criminals or people with malicious intent spoofing caller ID and breaking laws. These aren't legitimate organizations who obey the do-not-call list, or even sleazy telemarketing companies that are registered businesses. Since the numbers are most likely spoofed, they shouldn't be blocked in the first place and blocking them would only cause more harm than good.
It'll probably be a while before this problem is fully solved and it's easy to hold people accountable for this and track the calls all the way back to the origins.
The whitelist solution seems like the only approach for now, though I suspect only a very small number of people would actually be comfortable with such a system since you'll eventually miss an important call from your bank about fraud, or your insurance company calling from a new number, or any other million scenarios like that.