Recently, a conspiracy theory regarding CCTV at Hongik University Station on the Airport Railroad Express (AREX) line spread on social media.
It began late last month when a social media user posted a photo of a CCTV monitor at an escalator in Hongik University Station.
The photo appears to show a
real-time CCTV monitor at a station escalator, displaying green boxes and numbers over each passenger
. The user posted the photo with the sentence
"Has nationwide surveillance begun?" and raised questions, suggesting that a nationwide surveillance infrastructure was being introduced
.
The post spread rapidly, reaching nearly 200,000 views. Intense comments followed, such as "It has finally come to this," "Do we just have to suffer helplessly?" and "There's no choice but to overthrow it."
The SBS Fact Check team looked into what actually happened.
First, the poster claimed this was a case similar to China.
In fact, China is known to have begun developing a criminal tracking system using CCTV, dubbed 'Skynet' (Tianwang), in 2004
. There were also domestic media reports in China. China's state broadcaster CCTV reported in detail on its status as early as nine years ago. The report stated that China was building a system with over 20 million intelligent CCTV cameras installed nationwide, capable of identifying specific individuals not only through facial recognition but also through characteristics such as clothing and gait.
"China has already built the world's largest video surveillance network."
中国已经建成世界上最大的视频监控网
- Episode 5 'Sharing Moderate Prosperity' of China Central Television's (CCTV) six-part documentary "Amazing China." September 2017.
Naturally, concerns emerged. Multiple reports indicated that facial recognition technology was being used to monitor dissidents.
The National Endowment for Democracy (NED) in the United States released a report in February 2025, stating that such nationwide surveillance networks would undermine democracy.
Then what about the CCTV at Hongik University Station on the Airport Railroad?
Upon researching the CCTV at Hongik University Station,
it was true that, as spreading on social media, green boxes and numbers appear when people are detected near escalators by CCTV
.
The SBS Fact Check team sent a written inquiry directly to Airport Railroad asking about its purpose. Airport Railroad responded as follows:
AI CCTV uses trained object recognition technology to distinguish between passengers and luggage in video footage, and determines whether a passenger's hand is in contact with the luggage handle. If it determines that the handle is not being held, it displays a safety advisory on screen to alert passengers. When passengers are displayed on the advisory screen, their faces are blurred so they cannot be recognized. This system performs only the following functions:
· Distinguishing passenger and luggage objects
· Determining contact between hand and luggage handle
· Displaying warning screens in dangerous situations
- Airport Railroad, <Response to Inquiry from SBS Fact Check Team>, July 2026.
Given the nature of the Airport Railroad with many airport passengers, safety accidents involving luggage on escalators occur frequently. The explanation is that
when AI detects a passenger not holding their luggage handle, it displays a warning screen to prompt them to grab the handle again
. Since continuous automated announcements can cause fatigue and desensitize passengers to warnings, the goal was to improve the system to a responsive model that alerts only during dangerous situations.
They added that the green rectangles and numbers appearing over individuals during this process are
merely temporary identification tags assigned by AI to distinguish and track human movement in video footage, and faces are processed to ensure they cannot be identified
.
In fact,
Airport Railroad has publicly announced its AI CCTV accident prevention system multiple times
. For example, it issued a press release in November last year announcing a memorandum of understanding (MOU) with the Korea Transportation Safety Authority for intelligent AI CCTV technology development, which received extensive media coverage.
In June, at the "Symposium on Strengthening Cooperation Among Relevant Agencies for Railway Safety Management System" hosted by the Korea Transportation Safety Authority, Airport Railroad presented materials titled <Establishment of Object Recognition Intelligent AI CCTV System at Hongik University Station>, which contained the same details.
Looking at the symposium materials above, faces are rendered unidentifiable, and
the real-time CCTV photos circulating on social media were indeed the same. One can see that passengers' faces are obscured in yellow.
In response to SBS's inquiry, Airport Railroad added, "The AI CCTV being pilot-tested at Hongik University Station has no function to recognize faces or verify personal identities. Furthermore, the AI CCTV installed at Hongik University Station operates exclusively on an isolated internal network physically disconnected from the external internet, so data is not transmitted outside, nor is video recorded."
According to Ministry of the Interior and Safety data, around 650,000 CCTV cameras installed across integrated control centers in 217 local governments nationwide monitor every corner 24 hours a day. AI technology has been introduced in about 37.5% of these cameras, but it is not used to identify specific individuals or track their movements. The ministry explained that the purpose is to rapidly detect abnormal signs such as urban flooding and forest fires to prevent disasters.
In the AI era, it is natural for concerns over surveillance and personal data leaks to grow. Many hesitate to scan even a single QR code, and voices grow louder suspecting whether AI might be monitoring individuals without their knowledge. Citizens constantly monitoring and questioning power and technology can be a healthy attitude.
However, such suspicion must naturally be grounded in reasonable evidence. If unfounded speculation spreads into conspiracy theories, it excessively inflates social distrust, which can ultimately damage the health of democracy. What is needed even more in the AI era is neither blind trust nor blind fear of technology, but healthy suspicion based on facts.
Regarding the claim that "Hongik University Station on the Airport Railroad has CCTV monitoring citizens like in China," the SBS Fact Check team rates it as "False."
<References>
· Original post: https://x.com/morrisoi37/status/2080256340866515208?s=20
· China Central Television (CCTV) six-part documentary 'Amazing China' Episode 5 'Sharing Moderate Prosperity': https://youtu.be/5VE8-UJ1x5Q?si=BpJiPG9dNLj25Rw4
· National Endowment for Democracy (NED), <Data-Centric Authoritarianism>: https://www.ned.org/wp-content/uploads/2025/02/NED_FORUM-China-Emerging-Technologies-Report.pdf
· Radio Free Asia (RFA) "Chinese Police Use Facial Recognition Technology to Track Dissident Xu Zhiyong": https://www.rfa.org/english/news/china/facial-recognition-02172020173026.html
· Airport Railroad, Response to Inquiry from SBS Fact Check Team (June 2026)
· Airport Railroad Press Release <Airport Railroad-Korea Transportation Safety Authority Sign MOU for Intelligent AI CCTV Technology Development>: https://www.arex.or.kr/contentView.do?menuNo=MN202602270000000001&etcNo=&contentNo=CT202511120000000002&searchCondition=0&searchKeyword=AI&pageIndex=1
· Airport Railroad <Establishment of Object Recognition Intelligent AI CCTV System at Hongik University Station>: https://www.railsafety.or.kr/data/board/KnowledgeData_BoardList.do
· Ministry of the Interior and Safety Official Website for AI-based CCTV Control Support System: https://www.mois.go.kr/frt/sub/a06/b10/cctvBasedonAi/screen.do
(Writer: HYOJIN Kim, Intern: Park Geun-ho)
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