I definitely think that these scammers are getting their call list from the do not call list. I have talked to friends and family from many different parts of the USA who are all on the DNC and they get the exact same calls.
11/19/13 1:30PM Three rings and hangs up. Love my caller ID - never answer unknown names or numbers - if important caller will leave me a message. Time is money and three rings is all they can afford - need to call the next number hoping to scam.