“Personal data” is defined in Art. 4 No. 1 GDPR. This means any information relating to an identified or identifiable natural person. Data subjects are identifiable if they can be identified directly or indirectly, in particular by reference to an identifier such as a name, an identification number, location data, an online identifier or to one or more factors specific to the physical, physiological, genetic, mental, economic, cultural or social identity of that natural person. This includes all data such as telephone numbers, credit card or personal numbers, account data, license plate numbers, appearance, customer numbers, or addresses.