There was a time when the only people I heard saying "No no" were parents addressing young children. Now I hear it all the time. Not just "No, No." But also "No, no, no." And today I heard one of my coworkers speaking to a client on the phone saying "Oh no, no, no, no, no."
So I wonder how many consecutive no's are now appropriate. What happened to simplifying the language? Is the sky the limit?
Who knows how many no's before it's a no no?