I have both an unlisted number and have been on the TEXAS AND NATIONAL do not call lists since the beginning. The caller ID came up LIBORGDOTCOM. I answered and asked who was calling. The guy wouldn't tell me. I asked 5 or 6 times. HE TOLD ME HE DID'T HAVE TO TELL ME! And then hung up! I called back and got a recording that said if I didn't want to receive their product promotional calls that I needed to press one. I'm ALREADY on the do not call list! I'm suddenly getting a RASH of these types of calls.
Caller-ID only showed the phone number, a very brief robo message just said something like "We urgently need your donations to help fight for freedom, please visit our website (unintellible0" and hung up. I couldn't make out the name of the website well enough to even guess at it. These days the phone number is likely to be forged anyway.