That's no longer true.
Tax information isn't being posted online now in Sweden you can make a "FOIA" request but you have to have a legitimate reason now to obtain it.
The public tax records were too often abused for harassment, political extortion and plain crime such as burglary and fraud so they pulled the plug on online publishing of tax records.
Is this from personal experience? because from all what i could gather since 2011/2010 tax records are only issued on demand using a FOIA request form and you need to specify a legitimate reason to access them.
Do you get full W2 type info, or just the joint income of the family? It would be hard to tell a coworkers income if it is lumped in with their spouses income + investment income + whatever.. vs seeing line item income for that person.
As well as in Norway (although, the degree of "public" has changed somewhat: Initially it was published in newspapers, that turned out to be not such a good idea as newspapers started publishing on-line (hello: permanent, on-line database of income, open to all[1]). So then it changed to one having to log in to the government portal to look up individual tax filings - and now those you look up get a notice about who has checked their taxes.
I'm a little conflicted about the last part; on the one hand, why not give notice if someone's been "snooping" -- on the other hand it kind of defeats the purpose of having a transparent system -- how will your boss feel if you look up his/her salary? And should it really matter?
Always thought it was nice that one could check some employee/manager salaries before heading to a job interview. One still can, of course -- with the caveat that some might find it intrusive. But then, would one want to work for such a person?