Biometric categorisation systems that are based on natural persons’ biometric data, such as an individual person’s face or fingerprint, to deduce or infer an individuals’ political opinions, trade union membership, religious or philosophical beliefs, race, sex life or sexual orientation should be prohibited. That prohibition should not cover the lawful labelling, filtering or categorisation of biometric data sets acquired in line with Union or national law according to biometric data, such as the sorting of images according to hair colour or eye colour, which can for example be used in the area of law enforcement.