Early parts of this book focused on the simplest scenario: self-custody, where you're only holding your own digital assets. Many people will instead be holding assets in trust for other people, and this introduces a whole new level of fiduciary duty -- one that is discussed in this last Part.
An overview of Digital Custodianship Responsibilities provides the barest summary of this complex area of law, acting as a starting place for anyone who needs to delve more into the topic of holding digital assets for other people.
The Frank Family Fund Example then offers an example of how the risk modeling methodology of this course can be to resolve vulnerabilities in a more complex custodian setup. Note that all of the topics discussed to date remain relevant: the same risk modeling system can be used, the same adversaries can be dangers, and the same cold storage scenario can be applied to assets that don't need to be in a hot wallet. The Frank Family Fund thus demonstrates how this course's material continues to be relevant to increasingly complex (and realistic) custodianship scenarios.