The Privacy Commissioner for Personal Data , Hong Kong ( Privacy Commissioner ) , Mr Stephen Kai-yi WONG , expressed serious concern over the Cathay Pacific Airways data breach incident Attack.Databreach , noting that the incident Attack.Databreach might involve a vast amount of personal data ( such as name , date of birth , passport number , Hong Kong Identity Card number , credit card number , etc ) of local and foreign citizens . The office of the Privacy Commissioner for Personal Data , Hong Kong ( PCPD ) would proactively contact the airline and initiate a compliance check . The Privacy Commissioner advised the airline to notify the affected clients as soon as possible , and take remedial steps with details explained immediately . Mr Wong said that organisations must take effective security measures to protect the personal data of its clients . If an external service provider is engaged as a data processor , the organisation must adopt contractual or other means to safeguard personal data from unauthorised or accidental access , processing or use . Mr Wong reminded members of the public that if they find any abnormalities with their personal accounts of the airline concerned or credit card accounts , they should contact the airline and the related financial institutions . They should also change the account passwords and enable two-factor authentication to protect their personal data . Mr Wong stated that while reporting of data breach Attack.Databreach is voluntary , any organisation concerned is encouraged to notify the PCPD . By doing so , the PCPD can work together with the organisation to minimise the potential damage to clients .