... 2008, the ranking of the top 10 countries identified as sources of spam remained the same.34 The list of the 10 worst ISPs was less stable. Nonetheless, eight of 10 ISPs remained in the top, ... providers. Development of accurate measures of these flows is complicated by the large number of legal and illegal players and the elusive nature of some of the transactions. Most of the financial flows ... dependent on the cost of time of an employee, the skills of the organization and the individual user to deal with spam, the sophistication of filtering technology, and the audacity of attacks....