Internet hysteria over secret mobile footage, such as that of tram woman allegedly being racist, steals our sense of proportion

Do you remember when happy slapping was the big downer of video on mobile phones? When people would slap strangers for no reason, nothing but their own amusement? This was the sort of thing that looked like social breakdown, before the recession.

Now, phones have hit the reach of their powers. I don't mean you can have 10 different Facebook pages open at the same time. I'm talking about "digilanti-ism", the act of bearing witness and sticking it on YouTube.

The woman on a tram was the classic digilante event. Emma West is accused of railing against foreigners and swearing in front of children (this, it turns out, is the Huge Crime of public transport. We'll put up with anything, you can pretty much urinate into the luggage hold, but if you say any of those words which most of us say four or five times by accident in front of our own children, every day? well, that is just not on).

The internet went wild and Twitter nearly broke. A couple of things sullied my righteous enjoyment: first, it strikes me that she might be pissed. There has been a spray of public-transport racism on YouTube since West, and the people always look hammered.

In one, which was shot on Thursday, the events are so similar that I wonder whether it isn't deliberate parody racism, undertaken because that seemed like a good way to be both racist and hilarious, in the mind of an incredibly drunk person.

I can tell she's drunk, by the way, not by the slurring but because of the way she falls over when she tries to kick someone. What's the point of getting angry with a drunk person? It's like trying to reason with a cat.

The second problem is the awful sprawl of consequence: a sense of proportion is the first thing to go in an internet-hysteria event (I guess that would be true of all hysteria events). West was arrested after the outcry over the footage, then her bail plea was originally refused for her own safety (she had received many death threats). She was released on Tuesday, but at one point it looked as though she would spend Christmas in prison.

This tube worker was suspended for calling an elderly man a "little girl" (this is actually quite sexist, used as an insult? but that's not why they suspended him).

This whole viral process, where the internet reveals a person in all her badness and suddenly two million people hate her like death itself, seems manufactured. And I don't mind manufactured outrage, except where it lands people in prison, or loses them a job.

An even more vexed digilante moment is this week's Scotrail epic, in which Alan Pollock manhandled Sam Main off the train for alleged fare-dodging. Main said afterwards he did have a ticket but that it was the wrong sort, and that he had cut his face in the melee.

But certainly at the time, the assembled crowd were on the side of Pollock, aka "Big Man", clapping him in a weirdly muted way, as though nobody was quite sure whether or not this was a joke that would come back and bite them. But maybe it wasn't muted; maybe that's just what normal people sound like when they spontaneously clap.

Scale is another casualty of digilanti-ism; I'm not used to seeing real fights, filmed by a real person, with a real aftermath. I am used to choreography, moral absolutes and a crowd that is completely certain about everything. Fiction has dominated screens for so long, I don't really know what to make of truth. Plus I still don't know what is true. If Main had a ticket, then Pollock is just an interfering bully.

The fire of digilanti-ism is snuffed out by ambiguity, which is what makes the clip entitled Calm Martial Arts Guy v Dumb Ass Chav, the all-time classic: It features an obvious aggressor, who looks denatured by his own unpleasantness, and an obvious victim, who looks calm but not too victimy.

The victim, of course, triumphs. There's no comeback, no prison term, no animals harmed. Just an underdog, winning. Real-life conflict, when it works, has an edge of its own, which is that, in the act of watching it, we have made the justice mean something.

Otherwise it's just two guys fighting. If two guys fight in the forest when nobody's watching, what does that do for the natural order of things? Nothing; it's the spectator who makes the world fair.

I like that. Everybody likes that. But you know it's rubbish, don't you? Nobody ever made the world fair by hitting "like" on YouTube.