It can only work if the "company / slash individual" is a legitimate company which decides to obey the law. I am sure that the FCC will make the list of "do not call" numbers available to any telemarketing company that wishes to obey the law (free for the asking).
I'm getting recorded spam-calls about IRS-relief from "Sarah", almost daily, at the small company where I work. What a pain! Since I started documenting these calls to report them, I've notice that they call from a different number every time. So even if I find a way to block one of these numbers, the calls will still come.
Does anybody know the name of the company behind these calls? That way we can nail them.
The only way to stop them is to sue them. Todd Friedman is a California attorney who will work with you to sue these [***]. You can make a few thousand dollars for your troubles. Look him up.