[rhblake]

The mentioned websites contain at least the full name, birthdate, registered address and marital status of every Swedish resident (at least above the age of ~16?), with the exception of a very small percentage of people with protected identity (which you can only get if you're under a "serious and concrete threat"). They get this data straight from the government - it's all public.

Go to e.g. http://www.ratsit.se/, write "Stockholm" under "Var" and hit "Sök" and click on a name for an example.

You won't see the personal identification number ("personnummer") that we use for absolutely everything, however as tednoob mentions you can get access to this by paying for premium access. Or you can call the Swedish Tax Authority. They don't have the right to ask who you are or why you want someone's number.

[bemmu]

In Finland even salary and capital gains data is released. Newspapers compile high score lists from it each year. There might be some lower limit to how much you need to earn before your data becomes public.

Here's some select tidbits from the data in English: http://yle.fi/uutiset/who_are_finlands_top_earners/8427787

[vesinisa]

You can actually access the public tax information for anyone if you visit the tax office or call their free customer service. Newspapers publicise only the top earners, but nothing stops you from finding out how much your neighbour earned last year in income and capital gains, if you really want to (and I guess quite many want, Finland is after all known as the "land of million of enviers" in addition to the more famous "land of thousand lakes".)

[staticelf]

That is true for the Swedish sites/system as well.

[callesgg]

On http://www.upplysning.se/ you can get the full information. But you do have to register for a free account.