> ProtonVPN (operated from Switzerland) claims[1]: "Our security team has also identified at least one VPN service which is working on behalf of a state surveillance agency."
> If I had to guess, it would be PIA: the most popular, the most accessible, and the most affordable US-based VPN.
If I had to guess, the state surveillance agency-run VPN would be one that's still accessible from China. I understand (but I could be wrong) there are still a few that manage to evade the blocks and provide good service despite all the crackdowns. Chinese state security has many more reasons to want to watch domestic VPN traffic than the US does. Their motivation is proven by the fact that they've spent the effort to build and maintain the "Great Firewall," and crack down on VPNs that bypass it.
It would be reasonably clever for the Chinese to crack down on all the VPNs that they don't control, funneling all the "illicit" traffic to the few VPNs they do control. It would make spying, monitoring dissidents, etc. much easier for them.
The NSA and other US intelligence agencies probably don't care very much about anyone that's dumb enough to need to use public VPN. Seems like the only people who would care in the US are domestic law enforcement, like the FBI.