Every now-and-then we get a marketing call to sell us something. It's not very often because (1) our number is unlisted and (2) it's on the do not call register. It's ironic that you unlist your number (at a cost) in order not to receive solicited calls and then you have to list it in order to not receive calls.
Well I got a call today asking for money and I asked them where they got the number. It was on some list that they had because apparently we've been giving money to charity and the charity organizations share lists of people like us. I then mentioned that the number is on the do-not-call register. At that point the lady told me that she worked for a Non Profit and they are exempt from referencing the do-not-call list.