The European Union, which is currently struggling with the problem of illegal immigration into the territory of the Member States, does not have reliable regulations allowing for the verification of the identity of persons crossing its borders. SIS II, VIS or Eurodac systems, serving the security of each EU country, operate selectively and contain only certain categories of data in their registers. This article focuses mainly on the importance of protecting passport documents - documents confirming identity, including citizenship of a given country, giving the right to cross the border and stay outside it. As confirmed, among others, by the attacks carried out in Paris on November 13, 2015, the use of false passports allows terrorists to enter Europe, as well as the free movement of terrorists there.