As of November, Suomen Perintätoimisto have been contaminating the customer servers of TeliaSonera (inet.fi) with their spam. They openly admit the use of a purchased list from Bisnode.
TeliaSonera abuse response: “B2B spam is legal.” Perhaps so, but do you want your entire customer base to suffer because you allow a spammer to abuse the facilities used by everyone? Besides, the processing of outdated and erroneous personal information is illegal, and the spamming of natural persons is illegal as well.
The hosts involved are in 184.108.40.206/24.