With an increased general threat level affecting Sweden, the intelligence threat is becoming more pronounced. The large volume of publicly available data can potentially reveal information that compromises the protection of security-sensitive activities when combined. Through modern analytical methods, large volumes of heterogeneous data can be co-analyzed to infer information not explicitly stated in the original data. This creates challenges for secrecy and risk assessments prior to the publication of open data or public records. This report presents a study that takes an initial step toward understanding the risks to secrecy and protective security arising from adversaries' potential to exploit public data in an intelligence context. The long-term goal is to contribute the knowledge needed to conduct thorough and well-grounded secrecy and risk assessments that also address problems arising from public data. This preliminary study is exploratory in nature and provides an overview of intelligence operations, sources of public data, and methods for processing and analyzing collected data. The report also discusses additional areas and perspectives that must be addressed in future research, such as the extents of the data sets, techniques for advanced analyses, risk assessment methodology, competence needs, ethics, and law.