I'm on the bus because it's pouring with rain. It's crowded and filled with end-of-day smell. Finally, a seat becomes available and I sink onto it. Then I sigh. The woman next to me, about my age, is deep in FaceTime. She's going commando.

I'm on the plane on the way to Melbourne, economy. Next to me is a young man playing a violent video game on his iPad. He, too, is going commando.

On the streets, walking along, devices held high, a nation goes commando.

You might identify that phrase with its common meaning. Our understanding of going commando is about underwear and going without.

These people are certainly going without. Going without headphones. Which means every single part of their interaction is broadcast to everyone around them. Of course, it's hard to hear on a bus or a plane or on the footpath, so the sound is cranked to the max. Every "Hello! I'm on the bus!". Every sound that signifies a successful violent execution. All out there at full volume.

It's clear we no longer have boundaries of any kind. Our constant use of social media has deadened us to the possible risks of sharing everything with everyone. At any time on any of my social feeds, I'll read about bad hair, bad food, bad debt, bad sex. And this constancy of revelation anaesthetises us to the possibility than others are uninterested. We seem to assume we should all just share and share alike.

There is no longer a little switch in our brains that tells us we need to make judgments about what to share, so the "need to know" basis is finally debased. Young women talking about their rapists. Parents talking about how they wish they'd never had children. The angry. The naked. The hurt and the bleeding.

Now, public discussion leaves nothing undiscussed. Of course, all of these subjects are serious and worthy of focus and debate – but what happens next is rarely serious or focussed. What happens on social is simply a shit fight. I wrote to a former student of mine begging her to keep details of her private life private and was told to mind my own business because her social-media revelations were a way to "get some support".

Which is what we used to do with friends on the phone in the privacy of our own homes. I'm no privacy warrior. As the bloke from Sun Microsystems said 20 years ago: "You have zero privacy anyway. Get over it." Despite years of advocacy around this topic, we haven't improved on our ability to control what people know about us.

But now there are new levels of oversharing. Not just device to device. Not just with people we know.

I'm no wowser when it comes to using mobile phones in public places. I use mine constantly. Running from "thing I need to do now" to "thing I need to do next", my phone is a way for me to exploit the travel gaps in my working day. I've responded to work intensification by trying to multitask: walk and talk, talk and walk. But I usually do it with headphones in. Increasingly, I am subjected to both sides of a conversation in public.

The woman I sat next to on the bus that evening was dissecting the destruction of her daughter's relationship with a long-time partner. I'm assuming the woman on FaceTime was her daughter. I wondered whether the daughter realised we could hear every word she was saying, amid her tears and the bus noise. It was strange to observe how, for a few moments, everyone tried to ignore the conversation before the curiosity about what was happening drove everyone to try to glimpse the image on the screen, to concentrate hard on the heart-breaking conversation.

On another bus trip at another time, a couple were arguing. On FaceTime. No headphones. Of course, I've observed plenty of arguments in public places and even had them myself. But I wondered then – and now – whether the person on the other end understood how public this was. It's exposure made double.

I don't imagine we can go back. The degree of revelation and vulnerable disclosure has reached such epic heights it's hard to imagine going back to how it was before. When we kept some things to ourselves and didn't share everything. But does the person on the other end know they are being played in a public arena?

Fortunately, FaceTime is non-existent (or at least rare) on the kinds of flights I take. Not so the violent video games, where the executions rang loud around the cabin. I felt too mean-spirited to ask the crew to intervene.

But on the way back, there was another young man using his iPad without headphones. He was watching The Santa Claus. In April. Now there's a sacking offence.

Jenna Price is a columnist for The Canberra Times and Daily Life and an academic at the University of Technology Sydney.

Twitter: @JennaPrice

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