CtOS

Developed by Blume Corporation engineers, the  CT OS, or Central Operating System is a computer system designed to manage the infrastructure of Chicago during the events of Watch Dogs. CT OS 2.0 serves as its replacement during the events of Watch Dogs 2 in San Francisco, and subsequently CT OS 3.0 during Watch Dogs: Legion in London and beyond.

About
The CT OS is a very complex interconnection of electronic systems, such as computer servers, sensors and databases, that interact to manage the city-wide infrastructure of Chicago. Many systems are connected and controlled by CT OS servers, such as subway lines, traffic lights and surveillance cameras. Unfortunately, the CT OS is also the core weakness of the city, as it can be hacked into using backdoor programs or facial recognition malfunctions, and used as a weapon against the city and its inhabitants. CT OS also manages to obtain and store data of Chicago inhabitants, which it does via various methods, such as by retrieving user information stored on CT OS connected consumer electronics and by using Chicago's mass surveillance system. All of the information gathered by CT OS is stored in the control centers (data servers) located throughout Chicago.

Along with being able to tamper with the CT OS telecommunication towers, Aiden Pearce is able to access the information and the mechanism responsible for accessing and storing it in the control centres. Communication sites are placed between the control centers to promote the effective and efficient transfer of data over large distances. Although CT OS is successful in reducing the crime rate of Chicago, it does not protect the city as well as Blume claims. CT OS is also tied to a space satellite, which functions as a safety measure intended for the remote shutting down of the entire system if deemed necessary.

Successors
CT OS was upgraded to CT OS 2.0 with assumed upgraded security features after Aiden Pearce rebooted it. CT OS 2.0 was then installed in several other cities, including San Francisco and Oakland. Furthermore, by the time Watch Dogs: Legion takes place, CT OS 3.0 had become the dominant CT OS operating system worldwide, with use in major cities across the world, including London.

Controversy
One question that is frequently asked about the CT OS is: Who controls the system that controls Chicago? One negative that has been noted about the CT OS is that large businesses could use the data stored by  CT OS to maximize profits. It has also been noted that control of the system could fall into the wrong hands, like those of hackers such as Damien Brenks, T-Bone, Aiden Pearce and Defalt.

The fact that control of CT OS could fall into the wrong hands has clearly been brought to the public's attention by a hacking collective known as DedSec. The group hacks into the system and misappropriated its abilities to use it for its own purposes, such as invasions of privacy or data collection, simultaneously emphasizing the enormous power and security flaws of CT OS.

Systems controlled by the CT OS

 * Blockers and Road Spikes
 * Bridge Access
 * Electric Grid
 * Lights / Traffic Lights
 * The L Train
 * Underground and above-ground steam pipes
 * Crime Prediction System
 * Security Cameras
 * ATMs / Bank Accounts
 * TVs and Video Adverts
 * Citizens' Private Information
 * Cellular communications
 * Internet-connected devices
 * Facial Recognition
 * Power Transformers
 * Light Houses
 * Vehicles
 * Cell phones

Trivia

 * The  CT OS is mentioned in an Easter Egg in Assassin's Creed IV: Black Flag.
 * Despite being called the "Central Operating System" in-game, in the eBook Watch Dogs //n/Dark_Clouds by John Shirley, it is referred to as the "City Operating System".
 *  CT OS vehicles are rare to come by after completing every district access mission.
 * CT OS is the main antagonist of the Alone Digital Trip, where it takes over the city with an army of robots in a twisted form of martial law.
 * In Watch Dogs 2, the Profiler has been redone to look more visually pleasing, including an emoji to reflect the NPC's general mood. Vehicles also have their own UI box which states: company name, logo, car make & model, car category, and also its license plate number.
 * While the Chicago Police extensively relied more on CT OS scan, the San Francisco Police rely more on 911 calls and rarely seem to use CT OS scans.