On June 7, 2017, the Clinic filed an amicus brief on behalf of five former Massachusetts attorneys general in defense of a critical investigative tool known as a civil investigative demand (“CID”). The case involves a claim by Exxon Mobil that the current AG, Maura Healey, should not be allowed to use a CID to compel Exxon to release information regarding its historic climate change-related disclosures. In April 2016, Healey sent a CID—a type of civil subpoena—to Exxon under chapter 93A, the Massachusetts consumer- and investor-protection law. The CID stated that AG Healey was investigating whether Exxon had made “misleading statements to investors and consumers and/or failed to disclose information to investors and consumers with respect to its knowledge of climate change, the role of its fossil-fuel products in causing climate change, and the impacts of climate change on the valuation of Exxon’s fossil fuel reserves and other assets.” Exxon challenged the CID in Massachusetts Superior Court. In January 2017, a judge in that court ordered Exxon to comply with the CID; Exxon appealed this decision to the Massachusetts Court of Appeals. The Clinic’s brief, filed on behalf of five previous Massachusetts attorneys general—Francis Bellotti, James Shannon, Scott Harshbarger, Thomas Reilly, and Martha Coakley — explains the history and practice of chapter 93A and of the attorney general’s use of CIDs. It argues that CIDs are a critical investigative tool that the attorney general regularly uses to protect Massachusetts consumers and investors from fraud and other unfair and deceptive acts and practices and that Exxon’s arguments, if accepted by the court, would undermine the ability of the attorney general to perform this important function.