"Personal data shall be: (...) (c) adequate, relevant and limited to what is necessary in relation to the purposes for which they are processed (‘data minimisation’)." Cite
Regulation 2016/679 of the European Parliament and of the Council on the Protection of Natural Persons with Regard to the Processing of Personal Data and on the Free Movement of Such Data, and Repealing Directive 95/46/EC (General Data Protection Regulation)