China (Bozhou Police) Seize Over 400,000 SIM Cards Weighing 45.44 kg in Major Telecom Fraud Bust

Chinese authorities have dealt a significant blow to telecom fraud operations with the seizure of more than 400,000 SIM cards, weighing a staggering 45.44 kilograms, during a raid in Bozhou's Qiaocheng District, Anhui Province.

The operation, carried out on July 21 under the unified direction of the Bozhou Municipal Public Security Bureau, dismantled a criminal syndicate that had been using recycled SIM cards to facilitate international telecom scams through a technique known as the "phone bridge" (shoujikou) method.

Investigation

The Qiaocheng District police anti-fraud center first detected suspicious activity near the border between Qiaocheng District and Guoyang County, where an illicit call center was believed to be operating. Through intensive investigation, authorities identified a telecom fraud ring led by a man identified as Wang Mouhui.

On July 21, police launched a coordinated raid, first apprehending Ma, an out-of-province suspect who was actively setting up "phone bridge" equipment at the time of the arrest. Officers seized four mobile phones and over 100 SIM cards at the scene.Following leads from Ma's arrest, investigators subsequently detained the ring's key members, Wang Mouhui, Wang Mouyu, and Zhang, at Wang's residence, where they discovered the massive cache of SIM cards along with card-testing devices, data cables, and additional mobile phones.

Modus Operandi : How It Worked

Wang Mouhui had previously operated a second-hand mobile phone recycling business. During his recycling work, he discovered that many old phones still contained functional SIM cards that previous owners had failed to remove. Rather than alerting sellers or properly disposing of the cards, he began accumulating them, testing each card with specialized equipment to identify "active" numbers that could still receive calls and messages.The active cards were then fed into "phone bridge" devices, a technique where criminals use two mobile phones (or GOIP/VOIP equipment) connected by an audio cable or speaker relay to disguise international calls as local numbers. One phone connects to the fraudster via internet-based calling software, while the other, loaded with a domestic SIM card, places calls to victims. The result: victims see a local area code on their caller ID, dramatically lowering their guard.

The fraudsters behind the operation were believed to be operating from overseas locations including Cambodia and the Philippines. Experts and commentators have raised an important caveat: not all of these cards may have been operational.

A Growing Threat

The scale of this seizure highlights a critical vulnerability in the telecom ecosystem. According to industry data cited in media reports, approximately 17% of Chinese mobile users fail to deactivate or remove old SIM cards when upgrading phones.With over 200 million second-hand phones circulating in China's resale market each year, this creates an enormous pool of potentially exploitable numbers.

The 400,000+ cards confiscated in Bozhou represent just a fraction of a much larger problem. According to the Ministry of Public Security, as of the end of 2025, China's information and communications industry had investigated and disposed of nearly 200 million high-risk phone cards linked to telecom fraud, along with over 400 million internet accounts.

Industry-Wide Response

The Bozhou case comes amid a broader regulatory crackdown on telecom-related fraud. In February 2026, State Councilor Wang Xiaohong announced that authorities would maintain successive waves of crackdowns, "leaving no breathing room for telecom fraudsters."

Since December 1, 2024, China has also enforced the "Joint Punishment Measures for Telecom and Online Fraud and Related Illegal Crimes," under which over 20,000 individuals have faced financial, telecom, and credit penalties for their involvement in fraud-related activities.

Public Warning

Police have issued an urgent reminder to the public: always remove and destroy SIM cards before selling, recycling, or discarding old mobile phones.

According to the China Academy of Information and Communications Technology, over 60% of the cards seized in the Bozhou case were so-called "dormant but active" cards, numbers that had not been used for calls or top-ups in some time but remained technically valid and registered to former owners.These cards can be sold on the black market for as little as 10 to 30 yuan (approximately $1.40 to $4.20 USD) each and批量接入 "cat pool" devices capable of simulating hundreds of local numbers simultaneously for automated dialing and SMS campaigns.

Beyond the immediate scam risk, failure to注销 old SIM cards can expose former owners to identity theft, fraudulent loan applications, and ruined credit records. In one 2023 case cited by Anhui's communications regulator, a retired teacher discovered she had been fraudulently burdened with 58,000 yuan (approximately $8,000 USD) in online loans linked to a SIM card she had discarded three years earlier.

Bottom Line

The Bozhou seizure serves as a stark reminder that telecom fraud is not merely a high-tech crime, it often exploits the simplest of oversights: a forgotten SIM card left in a recycled phone. As authorities ramp up enforcement and carriers tighten distribution channels, individual vigilance remains the first line of defense.

All four arrested suspects, Wang Mouhui, Wang Mouyu, Zhang, and Ma, have been formally detained on criminal charges, with the investigation ongoing.