For years, I avoided driving my little girl home from primary school along University Street in South Belfast, where the Family Planning Association (FPA) used to have its offices. I didn't want her to see the images of aborted foetuses festooned in the trees that line the road, placed there by anti-abortion campaigners holding their regular 'prayer vigils' outside the FPA.
But these days it's increasingly hard to escape such images. Following similar stunts in the United States and Canada, anti-abortion campaigners have now hit on the idea of blowing the pictures up to a massive size and driving them around on the backs of trucks.
Today, a group called Abort67 will mount what it calls "the biggest abortion exposure ever seen in the UK" as a truck travels around Parliament Square in Westminster and up and down Whitehall.
So all the children who are on exciting school trips to London to visit Big Ben and the Houses of Parliament will also get to see what an aborted foetus looks like, inflated to a grand billboard scale. Very educational for them.
The people who indulge in such crude, callous tactics aren't worried about the disturbing effects of these images on young minds, or indeed on anyone else's mind. Their one-dimensional zealotry and fanaticism blinds them to the impact.
All they care about is the message - abortion kills - and as far as they are concerned, the end justifies the means. No doubt they see themselves as brave holy warriors for 'the truth'. They like to talk about "using principles from the history of social reform to expose the hidden injustice" of abortion.
But there is nothing remotely principled about assaulting people's vision with such sledgehammer propaganda.
Would we consider it morally acceptable for anti-pornography campaigners to drive round town with vast X-rated images on the backs of lorries, as a way of exposing the hidden injustice of female exploitation?
Would we calmly tolerate militant vegans displaying gigantic gory pictures of pigs getting their throats cut, on the grounds that this is 'the truth' about meat-eating?
Or should we say, 'No, we don't want this sickening stuff shoved in our faces as we go about our daily business'? We need to decide what, as a society, we are prepared to stomach.
Attempts to deploy the lurid anti-abortion posters have been thwarted before. For instance, Dublin and Cork airports refused to grant permission to the Irish Centre for Bio-Ethical Reform when it tried to hold anti-abortion "education projects", including graphic imagery, outside airport buildings.
In Toronto, politicians are considering taking action after hundreds of residents complained about giant placards of bloodied and dismembered foetuses which suddenly appeared all over town, courtesy of the Canadian Centre for Bio-Ethical Reform.
But there are limits to what the authorities can do. In 2012, two members of a UK anti-abortion group were arrested and charged under the Public Order Act, for displaying graphic abortion images outside a BPAS clinic in Brighton. They were subsequently acquitted, and a judge ruled that the police acted improperly when they confiscated the photo signs.
Many of us may consider such grotesque shock tactics morally wrong and ask why the police can't do more. It seems that the campaigners are free to flaunt this grim imagery as much as they like.
Yet their ugly quest to reveal the supposedly hidden 'truth' of abortion is pointless. They are telling us nothing that we didn't know already. Abortion does indeed kill a foetus. When women make the often very difficult and painful choice to have an abortion, they do so in the full knowledge of what their actions involve. They don't need a shrieking zealot with a gigantic sign to tell them.
Fortunately, most women in the UK are able to terminate crisis pregnancies before the foetus resembles anything like the images on these placards. For those who have the misfortune to live in Northern Ireland, and must therefore travel to access termination services, the wait is often that much longer, and the pregnancy that much more advanced - a fact that should be on the conscience of all who oppose the extension of abortion rights to these shores.
With monomaniacal arrogance, Abort67 says that anyone not wishing to see the images should avoid Parliament Square and Whitehall for a five-hour period today. Everyone else in the vicinity, including children, will be forced to witness them as the truck trundles by.
Many people will be disturbed by what they see. But the disturbance is all for nothing, because nothing good will be achieved.