The German government is pondering whether to purchase information about tax evaders - people who have money in Swiss banks but are not declaring nor paying tax for it in Germany - and pay 2,5 million € for the CD with personal information of some 1500 people. (Reported e.g. by Business Week.)
The interesting part here is that the information has been stolen by the person who tries to sell it. One would think that at least in common law countries (US, UK), using illegally obtained information would not stick in court so it couldn't be enforced - but on the other hand, even there, what does not stick in criminal justice system may still very well stick with the tax collector because for the state, tax revenue is a much more important thing than a due process as applied in courts of justice. Is it okay that a government purchases the proceeds of a crime, even if these proceeds can then be used to discover and prosecute other crimes?
And then an even more interesting question. Will the person who stole this information from a Swiss bank (apparently in Geneva) declare the purchase price in his/her personal income declaration? He/she is likely a Swiss resident.
If yes, the Swiss will have him/her; he or she could probably be prosecuted under some kind of data protection crime or at least misdemeanor, and proceeds of this crime could be confiscated.
If not, he'll be a tax evader and Swiss law enforcement should be entirely justified to require the person's details from the German government who is paying him/her. If the German government refuses, they are themselves protecting a tax evader. Hardly a justifiable position.
Perhaps someone could then sell the information to the Swiss? Whether that is a crime depends on the way the information was acquired, of course... we have a nice recursive crime.