Afaik Sweden is pretty transparent in that regard and it's completely normal to be able to check the employment status and income of other swedish citizens.
Norway too, leading to yearly "fishing expeditions" for newspapers writing about what celebrities earned and paid in tax.
The justification for this in Norway at least was that it's considered a social concern whether or not you pay your taxes, and that it was considered important that people should be able to trust that people around them also contribute.
But it's arguably shifted quite significantly in balance now that it's possible to look up online (and various restrictions have accordingly been put into place) vs. before when you used to have to go to the tax office and look it up in physical books - the latter took care of the public interest aspect while making it too cumbersome for people to do just to satisfy random curiosity (e.g. before it went online, I don't think I knew anyone who had ever bothered; afterwards "everyone" has probably looked up someone).
