It's not "limited scope". This information was obtained as part of a very broadly scoped illegal action. Also, this cut of data does not "target[] any specific crime" -- it will contain information on Danish citizen who are not in any way breaching danish law (either because they are using these shell companies for legitimate purposes, or because they aren't resident and thus not liable for tax, in Denmark). That initial action doesn't become "limited" just because the criminals filtered it down. This is exactly the same as NSA dragneting and then only passing on information when they thing they find something bad.

But even with that, "limited scope" and "targeting specific crimes" aren't magic get-out-of-jail-free cards. If I design (from a secure location that won't prosecute or extradite me for doing so) a worm to infect peoples computers, and once there, quietly scan these computers for evidence of pirated movies (very targeted, very limited scope) and only when it finds evidence of such does it phone home (and only with the evidence, nothing more is ever collected or shared). I then sell this information to an aggressive anti-piracy-litigator. Is this now OK, because it's "limited scope information about people breaking some specific laws - the information is verified to be useful by sampling"?

(Also, on laws: If the law can be changed willy-nilly to suit whatever the government wants to do, you don't have the rule of law. This is bad. It is doubly bad when you go and change the law, not because you have a principled belief that it's bad, but because it prevents you from doing a specific thing. In practise, this is the same as the law not applying to the government. The Danish constitution is tragically toothless, as most of the relevant articles contain the phrase "except where an special exemption is created in law" - for an example for the inviolability of the home, more than 200 such exemptions exists.)

Oh please. This is one of the few countries in the world where you can still hide your wealth and avoid paying taxes. Govnerments around the world are working on, and have for a long time, to create deals to exchange information. If what you're doing is within the law then SKAT gains zero new information, because they already know about every financial transactions they are supposed to know about.

Here SKAT had an oppotunity to gain that information anyway, and that is a clear signal to criminals that they shouldn't feel safe hiding behind some beneficial countrys laws.

Your example with a worm, is a straw man. Infecting millions of computers and shifting through it all to collect doubtful infomation is hardly the same. SKAT have been trying to get their hands on this infomation for decades, through legitimate deals. Now someone presents it to them via a different channel. If you want it to be comparable, it is someone infiltrating a torrent tracker and use information from that to sell to collection agencies. They still cannot use the information for anything but prompt a real investigation. After all we don't know if the information is real or not. If you want to do that, be my guest - I don't have a problem with it.

About the law, it cannot be changed willy-nilly, it still have to be voted for in the parliament.

The comparison is a country performing unethical things vs. paying another actor to do unethical things.

It sounds like you are making an "ends justify the means" argument, but I don't think that absolves them of supporting black hat activities.