Of the worst cyber attacks in American history, but industry sources tell NBC News that the majority of people whose phones and their metadata was breached have not been notified.

And as of now, there's no indication that there are plans to.

According to the White House, China's salt typhoon hack has now been underway for upwards of two years, hitting at least eight

of the major U.S. telecommunications providers.

Officials say only a few prominent individuals have been specifically targeted, and that no

classified communications are believed to have been accessed, but they are still warning all Americans to

only use encryption if you don't want hackers reading your texts or listening to your calls.

Joining us now, former director of the Cybersecurity and Infrastructure Security Agency and

Chief Intelligence Officer of Sentinel 1, Chris Krebs.

All right, Chris.

A Chinese hack that we have now been the victims of for more than two years.

How does that happen and how do we not know?

Well, I think the reality is the Chinese Ministry of State Security, who is allegedly behind this activity, this attack, is good.

You know, they are very sophisticated.

They are very capable.

They're very patient.

They're very quiet.

And they've been probing at all number of infrastructures here in the U.S. and elsewhere.

And they've obviously had a great deal of success getting into various telecommunications providers.

I think what's really this, well, the situation here is that we have a bunch of systems that are a mix of modern technology and hybrid legacy technology.

And as I understand it, they just were able to pick off some vulnerable edge devices,

just sitting at the edge of the public internet and the enterprise.

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