A "Trojan线路" refers to a hidden system or piece of software used in a network or system to intercept or disrupt traffic. It is part of a broader strategy to secure or monitor systems without exposing them to unauthorized access. This concept is often associated with a "Trojan horse" in programming, where a piece of code is hidden to be exploited later. Additionally, it might be related to a "trojan firewall," which uses specially crafted software to intercept and block malicious software before it can reach its target. The term suggests a hidden system designed to monitor or control network traffic, making it an essential component in network security measures.