The growth of sports analytics has made professional teams more and more reliant on proprietary data and algorithms, which are only valuable as long as they remain unknown to competitors. Teams are, however, relatively poorly equipped to protect these secrets. This chapter reviews five options available to teams looking to protect their secret information: league rules and norms, nondisclosure and noncompete agreements, trade-secrecy law, criminal law, and information-security efforts. None of the legal options are perfect, since breaches can be difficult to detect and legal remedies expose teams to unwanted publicity and risks of further breaches. Teams, then, should focus their efforts on building robust security systems to prevent problems from arising in the first place. The chapter concludes by discussing trends that are likely to increase the importance of information security in professional sports.