Since its launch in 1995, the majority of personal data held in the Schengen Information System (SIS) concerns third-country nationals to be refused entry to the Schengen territory. This study reveals why the use of SIS (and the second generation SIS or SIS II) entails a risk to the protection of human rights, such as the right to privacy and the right to data protection, but also the freedom of movement of persons and the principle of non-discrimination. This study describes the implementation of SIS in respectively France, Germany, and the Netherlands and the available legal remedies in both data protection and immigration law. On the basis of three general principles of European law, minimum standards are developed for effective remedies for individuals registered in the SIS, but also other databases such as Eurodac or the Visa Information System.