...or your association with "Occupy" or some other political protest movement that someone in power disagrees with, or that your wife bullied some politician's wife for two weeks in school, or that your interfering neighbour with a petty dislike of how you landscape your garden works as a government clerk and can access your data.

There are many reasons why some individual might want to know private things about some other individual. When individuals with some tiny (or vast) power want to wield it over anyone else, especially when they can do it with little oversight, it's very tempting.

That "the government" has access to my private information does not mean it's blind and faceless. It's made up of people with complex motivations.