Tech literacy is superficial; I *wouldn't* expect the police to understand that
"you'd hope the police would understand that once it's on facebook odds are that it has been duplicated for 'backup' purposes and is recoverable."
What makes you think they understand that? Stereotyping of the US police aside, I still wouldn't expect them to be notably more competent with technology than anyone else.
Plenty of people out there think deleting something in Windows literally deletes it beyond recovery. Some people even believe moving something to the recycling bin does the trick(!) It's not that likely they'd understand Facebook's storage setup. I suspect that even if they roped in one of their colleagues who considers himself an "expert" in technology because he knows all about apps and always has the latest smartphone, there's no guarantee that he'd be aware of this.
(tl;dr version of following rant- Understanding of the superficial aspects of modern digital technology is widespread these days. Understanding of even the most basic aspects of the underpinnings is far less so.)
I've said it before on several occasions, but don't be fooled by the apparent huge increase in literacy surrounding digital technology in recent years. It's true that the man on the street is comfortable with (and generally obsessed with) computers and digitally-powered gizmos in a way that only geeks were fifteen to twenty years ago. Everyone likes to consider themselves a "geek" now, it's cool.
I know how to set up and connect to a wireless network; look, it's in this Android menu!
But while everyone's rushing out to buy the latest boys-toy smartphone and knows all the hot apps to go on it, ask yourself this. How many of them really understand (or even *care* about understanding) even the most fundamental aspects of the underlying technology?
Case in point. If you asked a random sample of the general population- or even of the boys-toys gadget technophiles- to explain what "digital" *actually* meant at a basic technical level, how many of them do you think could give a proper answer? How many would think it was probably something to do with computers, a synonym for shiny modern technology or for online communications? (#)
I rest my case. (##)
(#) Hint; why do you think it effectively *has* become that synonym in general use, such that the Compact Disc- a system whose original selling point *was* that it was ******* digital is contrasted with "digital" (i.e. modern, online) methods of listening to music. Oh, I can buy it in digital form or on DVD? Would that be a ******* analogue DVD then? Let's be honest; most people probably don't *care* about things like this- what digital means, etc.- even if it's more fundamental than some aspect of their shiny, shiny gizmo.
(##) No more evidence needed, but ask yourself how many people could explain even the most basic structure of how the Internet is set up and the principles of its operation, and how many tech "literate" people really know which numbers to punch into which box, or how to select a WiFi network on their Android phone. Ask them what the difference is between the world wide web and the Internet itself.... etc.