The paper presents ethical dilemmas resulting from cases where the failure to share information places humans and/or property at risk. Examples from four domains are analyzed to examine similarities and differences. The central thesis of the paper is that deciding when information sharing is appropriate in the presence of risks is an ethical matter and policies and laws that inhibit sharing should be reviewed in this context. This presentation is in the context of SCENS (Secure Content Exchange Negotiation System), a new informationsharing framework that utilizes negotiation technologies to establish conditions for information sharing. SCENS allows for sharing that would not be possible otherwise due to lack of understanding of the importance of the information, legal limits on distribution, or risk aversion. The negotiation system enables communication and cooperation as it brokers agreements from sharing parties that determine who, what, how and for how long there is access to the shared information, and thus may serve as a tool for addressing ethical issues in information sharing.