This paper assesses the implications and practicalities stemming from the removal of land and sea internal border controls in an enlarged EU on December 2007. Freedom of movement represents a central feature of the supranational status of EU citizenship. Its practical application to the enlarged EU territory has constituted a necessary step to ensure equality among all European citizens. After providing an account of the processes and logic leading to the removal of checks at common borders, the state of play within the Schengen area is described. Particular attention is paid to the national security strategies carried out by the EU-15 member states currently in place and their consequences on the freedom of movement of individuals and on liberty. It is argued that by setting the removal of border checks as an important security challenge, we are witnessing the emergence of alternative and scattered security measures on the mobility of people which might weaken the Europeanisation processes inherent to the liberalisation of mobility inside the EU.