Economic growth, development of new technologies, in particular IT, intensified threats to this sphere of human being’s privacy which are personal data. Broadening the scope of data about citizens collected by various public and private institutions made it difficult for an individual to supervise the flow and contents of information about him or her. In the second half of the 20th century, fragmentary regulations related to the issues of personal data protection appeared in the legal acts issued under the auspices of the United Nations, though they referred rather to privacy protection than data protection sensu stricto. The European Convention on Human Rights of 1950 is such an international act. In Art. 8 it grants every human being the right to respect for his private and family life, his home and his correspondence, allowing for limiting this right in internal regulations only in case where it is provided in the legal act of statutory rank.