Seriously though, there should be a statute cited on the request you got. Read the statute and see if what they are asking is theirs to ask by statutory authority. If there is no statute cited, it may not even be from the government at all and might be a scam. (Like the gov't isn't already a scam, I know.)
You could simply "forget" to respond to the point they have to pick up the phone. Make them call you. Once you have them on the phone they'll get bored with your "I don't know" and "I can't recall."
What's the penalty for failure to respond? None probably. There's none for the 10-year census, just a nasty person waving an ugly stick at you. I made them interview me personally, because I refused to send in the form. I told the census taker how many people lived at my home, ages, and occupation and confirmed it all with the address. Any intrusive questions I simply responded with "You don't need to know that."
I am not aware of any statutory authority describing what you have, although my business got a Commerce Department census that wasn't all that intrusive to answer. Did it on line in fact.
FReegards!
