The twentieth anniversary of the area of freedom, security and justice (AFSJ) brings to light several transformations with regard to border management, and also several concerns that did not cease to reemerge twenty years after its creation. The term is understood to concern external borders and the reintroduction of internal controls within the common European territory. The attacks of September 11, 2001 consolidated the recognition of transnational security threats to be countered at a supranational level, considering that a national level administration would not be sufficient. The idea behind the construction of a common management administration of security threats relied on the protection of the entire single market. This is to say, an inadequate national external border control could undermine the collective trust and the free movement. The above-named fear of jeopardising the common market, enthusiastically advanced by France and Germany, became true in recent years following the apex of the migration crisis and the terror attacks in France in 2015. The reintroduction of internal border controls in several countries, the derogation from the Schengen Code for reasons of public security and the extension of the minimum period of internal border controls demonstrates a need of re-appropriation of the AFSJ. The reason for this stands behind the rationale of free movement within the area of freedom, security and justice, which has created a Common European Asylum System. This re-appropriation has to do with balancing freedom and security so that security does not take precedence over freedom. If policing internal borders is a matter dependent upon discretionary power, we cannot help but wonder whether migration flips between “crimmigration” and unilateral derogatory regimes to the disadvantage of fundamental rights. When it comesto internal borders, doesthis discretionary power of policing create grey zones of uncertainty?