In the "first half of 2016" (the most specific we're permitted to be), we received a subpoena from the Eastern District of Virginia. The subpoena required us to provide information about two Signal users for a federal grand jury investigation.
We've designed the Signal service to minimize the data we retain about Signal users, so the only information we can produce in response to a request like this is the date and time a user registered with Signal and the last date of a user's connectivity to the Signal service.
Notably, things we don'thave stored include anything about a user's contacts (such as the contacts themselves, a hash of the contacts, any other derivative contact information), anything about a user's groups (such as how many groups a user is in, which groups a user is in, the membership lists of a user's groups), or any records of who a user has been communicating with.
All message contents are end to end encrypted, so we don't have that information either.
This is the first subpoena that we've received. It originally included a broad gag order that would have prevented us from publishing this notice, but the ACLU represented us in quickly and successfully securing our ability to publish the transcripts below. We're committed to treating any future requests the same way: working with effective and talented organizations like the ACLU, and publishing transcripts of our responses to government requests here.
Below is the transcript for this request.