If it's run by the government, I'd probably fill it out. They can find out anyways if they want to, and I personally don't care what they know as long as they're responsible with the information. Having them know the number of bedrooms and bathrooms in your house seems to be overkill, but it's really insignificant to personal privacy.

On the other hand, if the documents fell into the hands of someone else, like they have in the past (in America and the UK, to my knowledge), I would be extremely angry with the officials who allowed it to happen.