제3자 정보 요청과 피고인의 방어권에 관한 小考 ― 미국 캘리포니아州 최고법원의 ‘Facebook’ 판결을 중심으로 ―

In the era of digital communication, social media platforms such as Facebook, Instagram, and X (formerly Twitter) have become integral to daily life. Since social media content, including messages, conversations, posts, photos, images, and videos, plays an increasingly prominent role as legal evidence in criminal proceedings, the legal status of third-party content shared on these platforms demands critical reexamination. This study begins with the recognition of this shift and thus examines how third-party content posted on social media may be accessed in relation to a criminal defendant’s right to a fair defense. The study focuses upon the landmark 2018 decision by the California Supreme Court in Facebook, Inc., et al. v. The Superior Court of San Francisco, in which the Court held that a criminal defendant may request access to social media content of third parties, but only insofar as it is publicly available, for the purpose of exercising their constitutional right to a defense. This groundbreaking ruling is the first to recognize that third-party content exchanged, shared, or posted via social media can no longer be exclusively accessible to investigative authorities. The 2018 decision represents a significant judicial attempt to expand the defendant’s right and signals a shift from the investigative monopoly over digital data held by law enforcement to a more balanced model of evidentiary access. It challenges the long-standing notion that only law enforcement agencies are entitled to access third-party content on social media platforms. The ruling not only marks the first judicial recognition of a defendant’s right to request such data independently, but also reflects an attempt to strike a constitutional balance between the defendant’s right to a fair trial and the privacy interests of social media users. Furthermore, the 2018 case may be interpreted as a constitutional effort to harmonize the conflict between two competing legal interests: the right to privacy of social media users and the defendant’s right to a fair trial. Thus, this study centers on the aforementioned precedent and provides a legal analysis of the U.S. “Stored Communications Act”(SCA) and related statutory interpretations. The study argues how a defendant’s request for third-party information/content within social media platforms relates to the constitutional right to present a defense, ultimately aiming to contribute to lay the foundation for future discussions on expanding digital defense rights in criminal procedure and informing potential policy reforms.