Book excerpt: The advent of computerized data systems, the growth of managed care, the AIDS epidemic, mandatory reporting requirements for child abuse, workplace drug testing, and various laws requiring that social workers maintain confidential communications in some situations yet disclose them in others have made confidentiality a vital, changing area of the law. Practitioners, administrators, and those studying for these professions need to know how to use these laws to protect their clients, themselves, and their agencies. Mental health practitioners need authoritative guidance in these areas when working with clients -- children as well as adults -- in both individual and group settings. Administrators must be aware of the laws that protect worker and client privacy, and those that permit legitimate access to information.