Without having even looked at the on-line census forms, I can imagine that omitting an answer won't work because the program won't advance to the next question/page if a question remains unanswered. Which makes it very difficult to opt out of questions you deem sensitive or invasive. At least with a manual form, you can debate the matter with the census collector and state that you refuse to answer certain questions because you have issues with them.
While some here have stated they don't have issues with the census being invasive, I have to wonder just why they need to have names. They haven't needed them for previous census' and the information they required was provided to their satisfaction at the time. So why the change now? I am suspicious about that aspect.
Where's my tin foil hat?
Skydrol - got a spare you can lend me?