Trafficking in human beings (THB) is a highly complex phenomenon which, according to the Palermo Protocol (2000), 1 occurs through a wide range of acts – recruitment, transportation, transfer, harbouring, or receipt of persons – by means of threat, the use of force or other forms of coercion, the abuse of power or of a position of vulnerability, or of the giving or receiving of payments for the purpose of exploitation. It is also described as an illegal underground activity, which can be discovered and detected sometimes only with great difficulty.