A lot of people have read in the pages of The National, Abu Dhabi, at this site and in the French media about the long trek across France made by a Abdelghani Merah to condemn the sort of extremism that led his brother into terrorism.
Abdelghani's marathon, with its echoes of the 1983 March of the Beurs against discrimination, ended in Paris yesterday, 40 days and - on his final count - 1,009km after he set off from Marseille. As you shall read, not everyone appreciated his arrival occurring on an anniversary of immense sadness.
He chose March 19 quite deliberately, believing it to offer a strong symbolic message, five years to the day since his brother Mohamed committed the most wicked of all his evil acts, the cold-blooded murders of two Jewish brothers aged six and three and an eight-year-old girl at the Ozar Hatorah school in Toulouse.
The father of two of the children, a rabbi and teacher, was also killed. The girl was the last to die, chased by her murderer into the school courtyard, caught by the hair and callously shot (with a second gun, the first having jammed).
It is a source of amazement to many who know him that Abdelghani Merah has risen above the violent hatred within his family, steadfastly resisted radicalisation and - after his brother's crimes - become a courageous fighter against Islamist extremism and terror.
He freely admits that his parents celebrated the September 11 2001 attacks on the USA and, along with one of his sisters and another brother, take pride in Mohamed's utterly cowardly acts rather than in his march. That other brother, Abdelkader, will stand trial in October accused of complicity in the 2012 killings, which ended only when Mohamed was shot dead by police in a siege at his flat.
And he knows that significant numbers of young Muslims living on French housing estates regard him as a traitor for turning against family members and regard Mohamed Merah as some kind of hero. It was against such entrenched attitudes, and the ability of ruthless recruiters to radicalise the young "with impunity", that he staged his walk.
As Abdelghani reached Paris, the route of his final stretch taking him past the Bataclan theatre, where other Islamist terrorists slaughtered scores of people on November 13 2015, a commemoration was being held in Toulouse, outside the school where those children and a rabbi had died five years earlier.
And this brings us to a sour footnote to the story of Abdelghani Merah, a man whose determination to use his detested family name in a good cause also prompted him to write a book entitled My brother, This Terrorist and subtitled A Man Denounces Islamism (available here though in French).
France Info carried an excellent report of his march, prominently featuring his noble words. It also interviewed Samuel Sandler, father of the murdered rabbi Jonathan, and grandfather of the two boys, Arieh and Gabriel.
"What do you think of (Abdelghani Merah's) initiative?" the reporter asked.
Mr Sandler's reply: "I am shocked. Not by his initiative but by the date he chose, To arrive on March 19 ... this man will once more highlight the name of his brother to the detriment of those of the victims. To choose this date is an indecent and obscene act."
I happen to think he is profoundly mistaken. I agree with Father Christian Delorme, a Catholic priest who helped to organize the March of the Beurs 34 years ago, when he tells me he finds Abdelghani "a beautiful person" and hails as a miracle that he was able to escape the "fundamentalist and murderous folly of his family".
But Mr Sandler also appears to be a good person. With the mother of another of Mohamed Merah's victims, a soldier of North African Muslim origin, he goes into French schools to talk to children. He tells them about "gratuitous hatred of which we see more and more" and of the need to remember the Second World War, relating the stories of family members - including his cousin, a boy then aged eight - deported to Nazi death camps.
I discussed this issue briefly with Abdelghani; he understood and respected Mr Sandler's view while remaining convinced he had done the right thing.
Someone so close to innocent victims is, of course, entitled to feel anger as well as grief. The loss he has suffered effectively places him above criticism and I can readily see the point he is making.
But I cannot help feeling it is a terrible shame that he could not have been more positive about Abdelghani's gesture, which - as well as raising awareness about the extremists who "steal the heart and minds of young people" - is a powerful statement against the hatred Mr Sandler identifies.