We all know that PGP is safer to use than privnote. I always assumed that privnote was still generally very safe though until the other day my friend was testing it out sending messages to our other friend over facebook. At first they were exchanging messages fine with no issues but then at one point all the messages started showing up as already "read" already even though neither person had read it yet. Any idea what had happened? I don't wanna put on my tinfoil hat quite yet but I can't seam to explain what else could have happened.
Facebook read it.
They have an automated script that fetches every link to cache a thumbnail. When that happens your message is read/deleted.
Use the password feature to prevent this.