This chapter looks at the process of the transformation of immigration into a "social problem", by analysing in particular the role played in the matter by politicians and security agencies. It then examines how migrants have been turned into "social enemies", by stressing the reasons and the criteria of this transformation. The chapter examines the process of the social construction of the "migratory threat". The demonstration of the multiplicity of the factors underlying the process of definition of the migratory threat can only call into question the current trend of the increasing reinforcement of immigration controls in Europe and, consequently, the role of the security agencies involved in them. It should be pointed that the transformation of immigration into a multiform threat to the European Union (EU) societies may satisfy collective needs and certain logics specific to the political market and the security agencies functioning, but it is far from ensuring the well-being and the smooth functioning of the societies.