NSA doing NSA things. All legal and kosher due to the Third Party Doctrine[0]

[0] https://en.m.wikipedia.org/wiki/Third-party_doctrine

> Netflow data can be used to track network activity traffic through VPNs

Does this mean so called non-logging VPNs are handing over data? That seems unlikely depending on the provider. Mullvad seems pretty solid and seems like they don't sell 'Netflow' data. But I could be wrong?