Hackers known as Salt Typhoon, linked to the Chinese government, have deeply penetrated U.S. telecommunications infrastructure, allowing them to listen to phone calls and read text messages.

The breach was first reported in early October by the Wall Street Journal, and it is considered by Senator Mark Warner as 'the worst telecom hack in our nation’s history.'

The hackers exploited the system used by U.S. authorities to wiretap Americans in criminal cases, but they were unable to monitor or intercept encrypted communications.

Fewer than 150 people have been identified as having their communications monitored, mostly in the Washington DC area, but the actual number of affected individuals could be much higher.

All major U.S. carriers, including AT&T, Verizon, and T-Mobile, were impacted, and the hackers are still present in the system, with no clear solution to remove them without replacing old equipment.