Nothing much. He expanded on what previous whistlesblowers talked about in early 2000s.

It’s more about the NSA. Can look into Projects Minaret and Shamrock. 1945-73 was a time of surveillance of US citizens.

A Review of Intelligence Oversight Failure: NSA Programs that Affected Americans

Plus this documentary about William Binney and his crew at NSA. They were the people who helped to create some of the systems Snowden talked about.

Good American. On you tube but May need a VPN

https://youtu.be/666wsDcoNrU

Otherwise look up projects Trailblazer, Thinthread and Solar winds.

Also look up Senator Church committee from 1975.

https://constitutioncenter.org/blog/looking-back-at-the-church-committee

Then CIA/media relationship. This is the start of the rabbit hole journey:)

So you’ll find Things he explained have been going on before he was even born. All that’s changed is the technology.