[ska]

> What's the difference?

There is an idea of balance of interests between the individual and the society. This is why for example your employer has to report salary data directly to the government but there are laws in place that control who else they disclose that too and under what circumstances. See also, for example, sex-offender registries, census gathering, etc.

NB: I'm not offering comment on whether or not the balance on those cases (or others) has been made correctly, just pointing out that it is a generally accepted concept in modern "western democracies" at least, and seems to be held by the majority of citizens unless you get pretty deep into the tails.