They aren't "watching", they spoof area codes to make you think the calls are local. The DNC works for legitimate telemarketers, people selling something. That is clearly explained on the sign up page. Did you read it? It also clearly tells you that criminals will ignore all laws and call you anyway. Did you take the time to read that?
Received a call from this #. They asked if this was (my name) and hung up when I said yes. I didn't return the call for fear of a call back charge scam.