I was looking at dead people on Las Ramblas presumably before their loved ones even knew they were dead. In my defence, I stopped looking once I realised what it was. Many people's understandable response to anything these days is to whip out the phone and start filming, and then post it. Presumably people feel that it is important to document these things, to show people the true horror, to bear witness. But then, you wonder, does it spread the virus of 'terror'?
We saw a similar phenomenon in Charlottesville last week, and in this case the witness footage seems to have been useful in ascertaining what exactly happened.
You can argue that in an era of fake news, documenting everything is the only way to try and tell the truth.
But sometimes it can feel like it just adds to the general sense of chaos. This has felt like a summer of chaos, and in ways that chaos feels bound up in the technology we all have in our pockets now. Everything is instant and amplified. Trump takes to Twitter immediately after Barcelona with his usual bizarre outbursts. Footage of dead, dying and injured human beings is zapped around the world. And the demands for 'everything now' mean that there needs to be instant updates. Haywire information of hostage situations and pictures of culprits who may not be culprits are seized on. It is as if getting the story fast, and reacting fast, gives us some illusion of control over it.
But even while the world was trying to figure out what happened on Las Ramblas, there was more in train at Cambrils. The news may happen in real time now, but we will always, it seems, be that crucial bit behind. We can all react quickly now, but just not quickly enough to stop it happening.
So what to do? Whip out our phones and react? But always a step behind. And as long as we are just one step behind then these guys don't care. They don't care about consequences, about getting caught or killed afterwards.
They just care about having that edge of a few minutes in which they can get their damage done, and in this case, to escape to more damage. What happens afterwards is almost irrelevant.
Terrorism prevention, in general, and how it impacts on our lives, all too often feels like it's one step behind - as if we are still trying to combat the weapons and methods of the past while the terrorists have moved on to new weapons and new methods. And they seem to make it simpler all the time, and use more and more of the implements of everyday life as their weapons.
So in response authorities have stopped us all from bringing liquids on planes. I'm vetted every time I get on a plane, even though there is, in reality, virtually no chance that an Irishman travelling with a wife and two small children is a terrorist. But I take off my shoes and my belt and have my bags and my person X-rayed.
And God forbid I should be allowed to bring a bottle of water anywhere.
The vast majority of these security checks do nothing to make the world a safer place. Does it make us feel safer? Does it feel better that at least we are seen to do something? Maybe, but does most of this activity actually prevent lots of potential terrorist attacks? Doubtful.
But even if it does, they will think of new ways to attack. Spain takes terrorism pretty seriously.
It has 3,000 people engaged in monitoring 1,000 suspected jihadis. There were plans, before this happened, for 600 additional operatives by 2020 focused exclusively on jihadism. Spain even knew that there was a real threat on this occasion. Jihadis, who regard Spain as lost Muslim territory, had been encouraged to avenge past crimes against Islam. Apparently, the CIA explicitly told the Spanish authorities in recent months that Las Ramblas was a target.
But even at that, what can it do? For all its intelligence, what was clearly a major, complex plot, involving multiple locations, butane gas and up to a dozen people, was fomented under its nose.
Admittedly there were obstructions in place on the street that possibly prevented the death toll from being much worse. And authorities got lucky with the gas explosion. And increased security in the aftermath prevented the follow-up attack from being even worse. But, in reality, even the Spanish were largely powerless.
Anyway, where do you stop with all this? How much do we need to make our societies secure? How much do we need to compromise modern life to try and stay safe?
Do we, for example, stop tourism, one of the fantastic liberties of the modern world?
Some of the locals in Barcelona and San Sebastian would argue we should anyway. They say it is making their cities uninhabitable. And clearly now jihadis have tourism in their sights also. Along with going to concerts and cafes and restaurants, it is part of the Western decadence they wish to wipe out.
But even if you stopped tourism, do you then decide we need to stop public gatherings completely? Tourists aside, there is an urge all over the world for the promenade, the passeggiata. In Cork it was called "doing Pana".
Call it whatever you want but people like to gather, often in the evenings, often with their kids, in places where there are lots of other people, and walk up and down, having an ice-cream, a drink, people-watching, sizing up the talent, checking each other out, meeting friends, bumping into acquaintances. Does that need to end, too?
Ask any of the advocates of the proposed large pedestrianised square in front of the Central Bank in Dublin and they will tell you that all great European cities need these plazas, these spaces where people gather. How many bollards do we need to put up if we wish to keep them? How many bollards do we need to put on Grafton Street?
Or indeed do we just give up on this human urge to gather? And do we give up on the human urge to travel, to see other places, to feel the texture of other peoples, to try and understand them a bit more, and to see the limitations of our own culture, by witnessing another?
Or do we need to stop the whole car rental game? Or do we need to stop young men from hiring vans unless they can prove extensively who they are and why they want them? But then they'll get the vehicles somewhere else, won't they? Or they'll find something else to turn into a weapon.
As fast as we try and neuter each tool, they will come up with a new one. And it doesn't even need to be sophisticated. If you are ruthless, the whole world is full of potential murder weapons. Most of the tools of progress can become murder weapons, with the internet, the latest tool, being perhaps the greatest murder weapon of all as it spreads the virus of lunacy and hate.
So what do we do? Whip out our cameras and bear witness, look at the footage and emote, and say that we will not be afraid, and we stand with the victims, as all the time we compromise our lives to try in vain to catch up, and, of course, we tell ourselves that it will never be us and it couldn't happen here.