This recent Corporate Counsel article: "What In-House Counsel Should Know About Cybersecurity Information Sharing" provides a helpful overview - geared toward non-cyber experts - of the various types of government and private sector cyber information-sharing mechanisms and platforms that have fairly recently evolved in the context of the active cyber threat environment. The article also walks through the types of cyber threat information that are commonly shared or sought to be shared (as distinguished from business-sensitive personal/private information), the most common company concerns about information-sharing, and related protections designed to mitigate those risks.
See also these private sector information-sharing initiatives; this WSJ article: "Big Banks Team Up to Fight Cyber Crime"; the DOJ/DHS updated Guidance, Procedures, and Privacy and Civil Liberties Guidelines issued in connection with the Cybersecurity Information Sharing Act of 2015 (Division N); this Cooley memo, which summarizes two of the key sections of Title I of the Act - specifically concerning sharing of information between/among the public and private sectors about cyber threats (including privilege and confidentiality implications), and liability protections for companies that monitor, share or receive cyber threat information; and numerous additional resources on our Cybersecurity topical page.