No you cant get in trouble for not mailing it in, even thought its in the Constitution. If you don't mail it in then someone, most likely from your neighborhood, will come knocking on your door and ask you to fill out the form. If you don't fill out the form your city/state may not get the funding or representation it needs due to population since most of the government spending is due to population. It only asks 10 questions based on who lives in the house, how old are they, race, and is the house owned, rented, etc. So fill it out and mail it back to help your state/city get what it needs. If you or anyone else has any questions feel free to message me, i can even tell you how to get a job with the Census Bureau. Hope i was able to help!
at 1:27 AM on Mar. 29, 2010