IPVanish says for example that they own and have physical control over their entire operational infrastructure, including the servers, unlike Unlike many other VPN services.
But there is one point I don't understand. We are saying "Be careful with US-based VPN Providers". At the same time, it's said:
Can someone explain me this please? It's really confusing.
The US is actually a good place to run a no-log VPN service. Legally, many other countries mandate VPN providers to log some information about their users. This is not the case in the US. One can more likely trust a US company that says they don't log, because legally they can get away with it. This was proven by the case last year, where PIA was unable to provide any information about a suspected hoaxer except for his/her general location of Southern California (many millions of people).
Just like you need to trust companies that say they don't log, you need to trust companies at their word that they actually control their infrastructure. At least in the case of PIA, we know they were not logging IP addresses as of last year and they are not legally mandated to.