The Census Wants To Know You
Are you one of the lucky ones randomly selected to receive one of the American Community Survey's from the U.S. Census Bureau? It's the 28-page booklet that reminds you, in several places, that "your response is required by law."
It says it only takes 38 minutes to complete, but you have to know things like how much you paid for water and sewer last year, how much you think your property would sell for if it were for sale and how much money you made last year in interest, dividends, net rental income, etc. ("Report even small amounts credited to an account.")
It also asks you for your name, address and phone number, to admit if you're in this country illegally, where you work and how you got to work last week.
As for what can happen if you don't respond, here's the legal citation:
(a) Whoever, being over eighteen years of age, refuses or willfully neglects, when requested by the Secretary, or by any other authorized officer or employee of the Department of Commerce or bureau or agency thereof acting under the instructions of the Secretary or authorized officer, to answer, to the best of his knowledge, any of the questions on any schedule submitted to him in connection with any census or survey provided for by subchapters I, II, IV, and V of chapter 5 of this title, applying to himself or to the family to which he belongs or is related, or to the farm or farms of which he or his family is the occupant, shall be fined not more than $100.
For more info, go here.