"Rather, I think the account matching described in the affidavit says the FBI could have identified which VPNs Lin used via orders to Google, Facebook, and other tech companies, and using that, obtained a pen register on PureVPN collecting prospective traffic. I don’t think what is shown proves that FBI obtained historic logs (though it doesn’t disprove it either)."

Source: https://www.emptywheel.net/2017/10/09/purevpn-doesnt-need-to...