NEW YORK (AP) As nearly 150 global leaders readied themselves to arrive in Manhattan for the U.N. General Assembly, the U.S. Secret Service was stealthily dismantling a massive covert telecom network scattered throughout the New York region. Investigators reveal that this system had the potential to disrupt cell towers, interfere with 911 calls, and cause widespread telecom chaos precisely when the city would be at its most vulnerable.

This network, composed of over 300 SIM servers featuring more than 100,000 SIM cards and situated within a 35-mile radius of the United Nations, represents one of the most significant communication threats ever identified on American territory. Authorities warn that such a system could have disabled cellular connectivity in a city heavily dependent on it for everyday functionalities, emergency services, and counterterrorism operations.

With foreign dignitaries occupying midtown accommodations and motorcades jamming Manhattan streets, the operation’s takedown underscores a burgeoning risk area: attacks targeting the unseen infrastructure pivotal to a modern city’s connectivity.

A broader investigation led to this discovery

The intricate network was exposed as part of an extensive Secret Service probe into telecom threats specifically aimed at high-profile government figures, investigators noted. Dispersed over various locations, the servers acted as clusters of simulated mobile phones, capable of producing mass calls and texts, overwhelming regional networks, and cloaking encrypted communications for criminal use, officials reported.

“The potential impact of this system cannot be overstated,” stated Matt McCool, the special agent leading the Secret Service’s New York field division. “If it disrupts cell towers, communication halts, right? You can’t send texts, you can’t use your phone. Should this coincide with any significant event related to the UNGA, exacerbated consequences for the city could unfold,” he elaborated.

Authorities stated that they have not discovered any direct attempt to hinder the U.N. General Assembly and are unaware of any credible threats aimed at New York City.

Forensic analysis is still in its early stages, but agents believe nation-state actors perpetrators from particular countries used the system to send encrypted messages to organized crime groups, cartels and terrorist organizations, McCool said. Authorities have not disclosed details on the specific government or criminal groups tied to the network at this point.

“We need to do forensics on 100,000 cell phones, essentially all the phone calls, all the text messages, anything to do with communications, see where those numbers end up,” McCool said, noting that the process will take time.

An extensive, expensive operation

When agents entered the sites, they found rows of servers and shelves stacked with SIM cards. More than 100,000 were already active, investigators said, but there were also large numbers waiting to be deployed, evidence that operators were preparing to double or even triple the network’s capacity, McCool said. He described it as a well-funded, highly organized enterprise, one that cost millions of dollars in hardware and SIM cards alone.

The operation had the capability of sending up to 30 million text messages a minute, McCool said.

“The U.S. Secret Service’s protective mission is all about prevention, and this investigation makes it clear to potential bad actors that imminent threats to our protectees will be immediately investigated, tracked down and dismantled,” the agency’s director, Sean Curran, said in a statement.

Officials also warned of the havoc the network could have caused if left intact. McCool compared the potential impact to the cellular blackouts that followed the Sept. 11 attacks and the Boston Marathon bombing, when networks collapsed under strain. In this case, he said, attackers would have been able to force that kind of shutdown at a time of their choosing.

“Could there be others?” said McCool “It’d be unwise to think that there’s not other networks out there being made in other cities in the United States.”