<p>The explosive expansion of drone technology has ushered in significant benefits across various industries, from commerce to recreation. Nonetheless, numerous security threats have also been unleashed by this trend, warranting the development of effective anti-drone systems. This review paper provides a comprehensive examination of expanding threats posed by drones in the form of weaponization, espionage, and smuggling contraband. In addition to kinetic technologies, jamming, spoofing, and directed-energy interdiction weapons, it discusses the array of modern anti-drone technologies, including radar, radio frequency detection, acoustic detection, and optical detection systems. The research also discusses integrated anti-drone systems, which combine multiple technologies to enhance their effectiveness. It also addresses the technical, ethical, and legal challenges these systems impose, such as resource and environmental constraints, privacy concerns, and regulatory bounds. The research closes by mapping the future of anti-drone research, pointing out emerging trends and technologies and the need for continuous innovation to counter shifting drone threats.</p>