They began doing this to me a couple years ago. I talked to a friend who worked for the Census, told her they kept coming to the door, calling and lying about who they were or who was in charge. She said write the to the Census B. back and tell them you will not be participating in the survey and to please inform The people coming to my door and calling me (i gave names) to stop harassing me as I have told them and I will not answer my door to anyone AND I told them I had caught them lying. Never got another threatening letter or door knock.