These difficulties include the "inbuilt" character of fraud on the Community budget, given the nature of the organization; difficulties with information technology; the scale of the problem; the lack of prioritization of the issue by member states; corruption within the political establishments of member states; and legal problems. The paper concludes with an examination of the available models for operational cooperation in the fight against fraud. These models are the K4 Commission established under the Maastricht Treaty, the SIRENE bureaus, Interpol, Europol and the Unite Contre la Lutte AntiFraude (UCLAF), and the Commission's own anti-fraud unit. National police investigators have also established their own cross-border networks to combat the changing modes of cross-border crime. These efforts, however, raise questions about national sovereignty and accountability. 31 footnotes