WSJ: Dozens of Countries Hit in Chinese Telecom Hacking Campaign, Top U.S. Official Says

https://www.wsj.com/politics/national-security/dozens-of-countries-hit-in-chinese-telecom-hacking-campaign-top-u-s-official-says-2a3a5cca

Chinese government officials have denied responsibility for the hacking

Anne Neuberger, President Biden’s deputy national security adviser for cyber and emerging technology

“We believe that the voluntary approach has proved inadequate for the most critical companies that underpin our critical infrastructure. So we want to complement CISA’s efforts with regulatory efforts."

We're still talking about the hack which was caused by the
government's regulatory insistence on a "lawful intercept" capability,
right?

Failing to find a list of providers that were hit. Anyone know more ? I don't see them mentioned.
Verizon & AT&T I know of.

CNN mentioned Lumen. T-Mo?

I suspect that a gag order has been issued for the other companies, and a cybersecurity incident response team has already been hired and is in place.

There’s been a question about T-Mobile being part of this or not. I have no specific knowledge, but just count the number of times they’ve been hacked in the past (that we know of) and draw your conclusion that they’re part of this.

Ryan Wilkins

Here is the public Breach Report for T-Mobile. https://firewalltimes.com/t-mobile-data-breaches/
Unable to find AT&T, Verizon or several other companies on the list.

I was wrong. Here is a list:
https://firewalltimes.com/att-data-breaches/
https://firewalltimes.com/verizon-data-breaches/
https://firewalltimes.com/google-data-breach-timeline/

Over the past 25 years, security researchers worldwide have consistently identified new SS7 vulnerabilities (thank you AT&T) each year. Furthermore, at BlackHat around 2006, a researcher revealed several major vulnerabilities in law enforcement tools, techniques, and technologies.