I have noticed NORC U Chicago on my Caller ID and mostly it was during the day. Tonight I made the mistake of picking up (8:28pm) and someone started off saying his name and he was representing the CDC. I hung up. Whatever he was selling, I'm not interested.
After reading the comments here, I don't remember ever receiving a letter stating I was "selected" to participate. I did go their website (www.norc.org) and they seem to be conducting quite a number of surveys.
Fine, it's a legitimate organization; however, I have an unpublished number and really do not want them to call (I'll be reporting them to the FCC). So, I guess they will be hearing nothing but ring tones until they get sick of it.