The "do not call" registry is not a call blocker. Legitimate businesses will not call you when they see you are on the list, which does cut down on the number of unwanted calls you receive. Scammers, many of which are located in places other than the United States such as the Indian Subcontinent, don't give a rat's patootie about the do not call list, and since they are somewhere overseas are practically impossible to take legal action against.