Art. 16 II Treaty on the Functioning of the European Union:
2. The European Parliament and the Council, acting in accordance with the ordinary legislative procedure, shall lay down […] the rules relating to the free movement of such data. Compliance with these rules shall be subject to the control of independent authorities.
The rules adopted on the basis of this Article shall be without prejudice to the specific rules laid down in Article 39 of the Treaty on European Union.”