I installed signal on my phone with some enthusiasm, but it's
   practically useless because no one around me adopted it yet. It's sad
   that once a "social" app dominates the market, it's very hard to get
   people to switch to better alternatives unless there is a security
   scandal or something. Same goes with ring...
   4:53 AM, July 29, 2016, Rayzer <rayzer@riseup.net>:

     Apple’s iMessage too! ("Signal leaves virtually nothing.")
     Quote source @thegrugq, Twitter
     https://twitter.com/thegrugq/status/758833939020521472
     WhatsApp Forensic Artifacts: Chats Aren’t Being Deleted
     Posted on July 28, 2016
     Sorry, folks, while experts are saying the encryption checks out in
     WhatsApp, it looks like the latest version of the app tested leaves
     forensic trace of all of your chats, even after you’ve deleted,
     cleared,
     or archived them… even if you “Clear All Chats”. In fact, the only
     way
     to get rid of them appears to be to delete the app entirely.
     To test, I installed the app and started a few different threads. I
     then
     archived some, cleared, some, and deleted some threads. I made a
     second
     backup after running the “Clear All Chats” function in WhatsApp.
     None of
     these deletion or archival options made any difference in how
     deleted
     records were preserved. In all cases, the deleted SQLite records
     remained intact in the database.
     More, including 'How WhatsApp Can Fix This':
     http://www.zdziarski.com/blog/?p=6143

   --
   You’re not from the Castle, you’re not from the village, you are
   nothing. Unfortunately, though, you are something, a stranger.