In forensic science there is a concept called Locard's exchange principle, which basically states that every criminal will leave something at a crime scene, and take something away from it. From a classically forensic standpoint, that means DNA, fibres, fingerprints, etc.

It’s not just criminals, though. All humans are in a constant state of exchanging stuff in their environments, literally and metaphorically. For better or worse, we always leave a mark, and we are always changed.

In our world, you could consider garbage to be the full expression of the exchange principle. After all, garbage is stuff we picked up, used, then left behind. This helps explain why garbage is a gold mine, archaeologically speaking. We tend to learn the most about people and places of the past from their detritus. 

These days, though, much of our environment and many of our exchanges are digital. To get a real sense of who we were, how we lived and what we worshipped, archaeologists of the future will need to access servers and hard drives as much as landfills. 

Now, we might have content catastrophes like MySpace losing years' worth of content. Or old sites and platforms from the “original” internet vanishing into the ether. But humans’ digital exchange is still going strong. What we continue to leave online tells some interesting stories. What we take with us from the digital realm is, frankly, reshaping society.

I’ve been thinking about humans’ digital exchanges a lot since I happened upon this Tumblr post. It posits a rather creepy and evocative identity and meaning for the internet. I saw it first thing in the morning, which is way too early for that kind of kick in the psyche. My brain tends to think of internet content of yore more like a dusty box of forgotten stuff in the attic, rather than a graveyard or haunted house. But… it’s not wrong. 

In one way, the haunting notion makes more sense than the garbage dump, since we can’t or don’t often get rid of stuff online when we no longer have a use for it. We can’t declutter our entire digital footprint, KonMari-style. We just... stop logging in. 

On the flip side, The Reply All podcast recently had an episode that looked at moments and content that people would love to get rid of, and have tried, but can’t, for one reason or another. There were some pretty cringe-worthy examples. (Yet another peril of keeping all your stuff on platforms you don’t control.)

Now, there are varying degrees of the desire to delete when it comes to online content. There’s stuff that’s just embarrassing, but fairly pedestrian. Who doesn’t have something like that, really?

Then there’s stuff that does have more lingering influence. Like the woman interviewed in the Reply All episode whose professional brand has been rather tainted for a decade thanks to certain published marital advice from her younger and more naive self.

Of course, one could argue that a situation like that is still much more innocuous than the choices some people – especially young people – are making and the things they’re saying and doing online. 

Porn would probably still be the most glaring example, but thanks to social platforms and always-on media, there are now myriad ways to impact your personal and professional future.

To take a current example, someone like Lindsay Shepherd has exhibited sufficiently egregious online behaviour to get her Twitter account suspended indefinitely. (I am not going to get into her story. You can google her if you’re not familiar.)

She has expressed specific views in many public places and aligned herself with particular people. The record of that isn’t going anywhere. She’s also still in her 20s, and has her entire life and career ahead of her. 

The personal and professional reputation she’s built for herself is going to accompany her. It will have significant influence on consequences and opportunities, regardless of how her opinions, words and actions may evolve (or devolve) over time.

And people used to think tattoos would be the worst thing The Kids These Days could do to negatively influence their job prospects…

The internet can also enshrine experiences we go through that we would prefer not to remember. Or at least not remember that way. Like circumstances that lead to people having to crowdfund out of desperation to save a loved one’s life. 

It would be hard enough remembering back to that time if everything worked out. But what if it didn’t? What if, per the New Yorker article, you were one of those whose story didn’t tug enough heartstrings? Would that not make the record and recollection of such an experience even more painful? 

Still, that dusty virtual box of online content could be a silver lining despite a painful experience. Going back to that Reply All episode, the hosts also interviewed a man who’s scouring social platforms and other sites for words, pictures, video – any bits of his teenage son’s presence.

It’s what little he has left since his son died suddenly a few months ago. Throwaway content probably forgotten about, which, despite the pain that must accompany it, has become an invaluable gift to a grieving family. 

It reminded me of another show I listened to a while back where parents whose son had been killed in the Pulse Nightclub shooting in Orlando kept his voicemails. They were the only reminder they still had of what he sounded like. Love you, mom. Bye...

It made me think about platforms like YouTube and how many videos on there could be similar shrines to people who have died, lingering reminders of how someone spoke, laughed or walked. 

It makes you want to take an inventory of your own digital archives. Who’s there? Who’s not there enough? How much risk is there of losing access to it? 

The internet may be haunted, but that’s just another effect of the exchange principle. We built and inhabit it. Thanks to our technology, we’re Schrödinger’s humanity, perhaps more entangled with each other and our world than just exchanging. Destined to remain visible and audible, whether alive or dead.

M-Theory is an opinion column by Melanie Baker. Opinions expressed are those of the author and do not necessarily reflect the views of Communitech. Melle can be reached on Twitter at @melle or by email at