In this case the pin is the person identifying date. If such a database system was used at place and in time of the incident, it is known how many individuals a

In this case the pin is the person identifying date. If such a database system was used at place and in time of the incident, it is known how many individuals are affected and what data got out. It is just not known which individuals in specific. Should be common to send a notice to all individuals then and explain the details so those who are affected do know and can act.