Further to the adoption of the Luxembourg Law of 13 January 2019 ("UBO Register Law"), the UBO register is about to become a reality in Luxembourg. As from 1 September 2019, the public will have access to information such as the UBOs' identity and the nature and extend of the beneficial interest held, and this, without necessity to establish a legitimate interest. This free access to private data raises a number of questions in terms of data privacy. The proportionality of such a measure is in particular very debated.