They send you a letter in case you don't want to be part of it. How do I know if they sent it to my old address or that I didn't get the letter? Why should I be bothered to sort yet another thing out by responding to a letter? what about people who just forget about it? What difference does the actual idea make – if you want the data base for yourself – you can write a letter to them and get it done that way around.
As it says.