“Public policy is an unruly horse to ride”. 1. In the past the Court of Justice has striven to “tame” the wild horse in the context of the free movement of persons by striking a balance between the individual’s right to free movement and the legitimate prerogative of Member States to combat threats to public policy. The result of this compromise is now found in Chapter VI of Directive 2004/38/EC, governing the expulsion of Union citizens, in particular in its Article 28. 2. While consolidating the case law of the Court, Article 28 innovates by granting an exceptional level of protection for Union citizens resident for more than ten years in another Member Sate.According to Article 28(3), “An expulsion decision may not be taken against [these] Union citizens, expect if the decision is based on imperative grounds of public security”.