Heh. I just got the UK census documents, and reading through the questions I've got to wonder what the point of half of them is?
What is the government trying to learn?
There's a lot of issues that have just as much impact on people's lives that the census doesn't ask about, yet they feel the need to ask people's religion, ethnicity, and job description...
Sometimes, I wonder how they decide which questions merit being on the census and which don't.
Also, I'm reminded of my mother's paranoia about census information...
She refuses to put her name on a census form. Yes, she is paranoid, but not without reason;
She's dutch.
And one of the most thorough modern census serveys ever conducted was done by the dutch government in the 1930's.
The dutch government had no ill intent, and the census was conducted for perfectly legitimate and harmless reasons.
But, Germany invaded the netherlands just a few years later, and in the process got a hold of everything the dutch government had.
Guess what the census data was used for?
I'll give you a hint: Of all the Jewish communities in Europe, the most thorough extermination happened in the Netherlands.
Of course, these days, Census data is kind of trivial compared to what companies such as Google might know about you...
It doesn't matter if you can trust the companies or governments that collect this data, if you can't be sure who will get hold of it in the future.
After all, it wasn't the Dutch government that abused their census data...