Expectations
I'm a cynical curmudgeon. I fully expected that my "private" chat messages would be screenshotted by my "friends" in the conversation, overseen by Facebook employees and hackers, and archived by my buddies at the NSA.
Never, not in my wildest dystopian nightmares, did I ever dream that 3rd-party "apps" used by my dumbass "friends" could download all my chat conversations with them.