Every time someone mentions a VPN provider in my techie social circles, the "A VPN doesn't protect you" crowd piles in, usually with links to something like: https://gist.github.com/joepie91/5a9909939e6ce7d09e29 I don't understand this argument, but would like to. I run https://everytwoyears.org , a political non-profit focused on ending the warrantless metadata collection of U.S. citizens' communications. From every…
A VPN is just a tunnel from one point to another. You'd have to establish why the remote end is more trustworthy than the local end. Being located in a hostile jurisdiction may be somewhat protective, but it would also seem likely that compromising foreign VPN services is within the NSA's wheelhouse.
This is the explicit danger of VPN providers. Even if the provider is not complicit (which I believe applies to the likes of Mozilla), it still creates a centralized aggregation site for collection.
I'm not even sure a US-based VPN provider is safe. GCHQ just conducts the interception and would share the data with NSA. At that point, you are at the mercy of the NSAs locators being good enough to flag your tunneled traffic as "reasonably a US person" so it gets excluded.