发现不对劲！他马上打给12339

Group 1 - The article highlights a suspicious food delivery incident involving a request for photos at a sensitive unit, which was reported by the delivery person to national security authorities [1][3]. - The customer was attempting to exploit the delivery person to gather information about the sensitive unit due to a personal dispute, demonstrating a lack of awareness of the unit's confidentiality requirements [6]. - The article emphasizes the importance of vigilance among delivery personnel regarding unusual requests that may indicate potential threats to national security [6][9]. Group 2 - Specific warning signs include requests for photos of sensitive locations, such as government buildings and research facilities, which could compromise security [6][7]. - Other red flags involve the delivery of unknown items, such as USB drives or documents, alongside food orders, which could be used for espionage [6][7]. - The article also notes that high rewards for vague delivery instructions may indicate suspicious activity, particularly if the delivery involves sensitive areas [7].