The census form does not ask about immigration status, and the information is confidential.
http://www.freerepublic.com/focus/news/2466641/posts?page=3
Thug-o-crats seek-and-destroy ‘Birthers’
Hawaii Wants to Fine Me After Framing Me [a fellow FReeper]
http://www.freerepublic.com/focus/f-bloggers/2466896/posts
“The Office of Taxation wants to fine people who are labeled ‘vexatious requestors’”