Ever heard of the Reddit Warrant Canary situation?
Specifically, the 2014 Transparency Report read:
As of January 29, 2015, reddit has never received a National Security Letter, an order under the Foreign Intelligence Surveillance Act, or any other classified request for user information. If we ever receive such a request, we would seek to let the public know it existed.
This verbiage has been removed in 2015.
Reddit "probably" (absolutely) received a National Security Letter with a gag order not to disclose that they had been compelled to share anything with the government. I wouldn't be surprised if the Government could also tell them to let their logging software sit there on their VPN services as well and force them to not tell their customers.
Edit: this is such a great post from /u/noggin-scratcher explaining it, I'll include it here:
A National Security Letter is a request for information from the government for national security purposes, and they can include a 'gag order' saying that you're not allowed to tell anyone that you've received one or what information it was asking for.
But they can't force you to say you haven't received one - you're just not allowed to say that you have, so each year you include a line in your report:
• 2014: I have never been compelled to give information to the government
• 2015: I have never been compelled to give information to the government
• 2016: <conspicuous empty space where that line used to be>
Then someone asks you "Hey did you remove that line because you were compelled to give information to the government, or because you were just bored of including it?" and you say "I can't tell you that"
The implication becomes clear that there are only two plausible reasons for you to be acting that way. Either you've received an NSL, or you're playing the fool and want everyone to think that you have.
In the absence of good reasons to suspect fool-playing, we conclude that there's probably been a secret government info-request at some point.
NSLs are a somewhat controversial little tool because of all the secrecy involved (makes it very hard to be sure they're following proper procedure when no-one's allowed to talk about it), which is why people are bugging out a little. Even though the odds for most of us of being the subject of such a request, out of all the users on all of Reddit, is vanishingly low.