This article discusses the issue of illicit operations, which are activities that operate outside of the law and have a significant global impact. These operations include drug trafficking, human trafficking, illegal mining and fishing, wildlife trafficking, money laundering, counterfeit goods production, organ trafficking, identity theft, and weapons trafficking. The United States National Science Foundation has funded research grants to combat illicit operations, and this special issue highlights papers that have developed analytical approaches to detect, disrupt, and dismantle these operations. The papers cover a range of topics, including counterfeit goods, drug trafficking, human trafficking, and wildlife trafficking, and provide valuable insights and strategies for combating these illicit activities. [Extracted from the article]