Flynn copied Tron, a security program from the ENCOM mainframe, to the TRON system to act as head of system security and maintain order. After the emergence of the ISOs, Clu and several system monitors performed terrorist attacks against ISO-populated areas of the Grid. Despite this, most system monitors continued to perform their role of protecting the TRON system.
Tron and his long time friend, Dyson, were a part of a team of security programs. When many Basics discriminated against ISOs, Tron's team went to the area in which the discrimination was taking place and try to stop the harassment, as Tron disciplined the Basics however, an Identity Disc hit a Basic in the crowd, provoking a riot towards the ISOs. Tron's team immediately pulled out their Shields and attempted to prevent the Basics from doing harm to the ISO, these attempts were in vain however, and Dyson was scarred by an Identity Disc during the ensuing chaos.
Flynn created a new system monitor, Anon, in an attempt to get the issue between ISOs and Basics under control, and after Rezzing, he was accompanied by Tron. When Quorra attempted to meet up with the soon to be installed, Radia, she was prevented from doing so by two System Monitors, who had denied her due to lack of authorization. Frustrated with the Monitors, she decided to "Get authorization", which had made Tron skeptical enough to send Anon to find out what she was attempting to do.
More System Monitors were present during the celebration of Radia's installation, though they were soon commanded to hold off the newly arrived Virus, Abraxas by Clu 2 after he attacked the ceremony. Abraxes Derezzed the Monitors however, and as he approached Clu, CLu commanded a System Monitor to severe the stage between them, though this Monitor was also derezzed. Abraxes was eventually defeated by Anon, who was the last known System Monitor after various Programs were either Repurposed into joining Clu's army, or become Sentries willingly.
