Forty-five state attorneys general, including New York AG Eric Schneiderman, want phone users to be able to block calls they don't want. In a joint letter to top executives at AT&T, Sprint, Verizon, T-Mobile and CenturyLink urging them to offer call-blocking services, the attorneys general point out that a recent Federal Communications Commission clarification allows telecommunication companies to offer customers to ability to block unwanted calls and that such a service doesn't break federal law.