The blog author is in Finland, so it's covered by the Article 8 right to privacy of the ECHR. The exact implementation is country dependent, I don't know how it works in Finland but in the UK we just extended the common law tort of "Breach of confidence" to it.
That is very surprising to me. As far as I know, in Finland details of your income are publicly available, but someone reposting publicly available information is illegal.
