Aviv is two, her hair garlanded with flowers. Kfir is nine months old, playing with a rattle. Amelia, five, offers a cheeky smile. Eitan, 12, clutches a puppy. They are among the innocents, who may number 200 or more, abducted by Hamas. Babies, children, the elderly, a Holocaust survivor — the most vulnerable — now trophies paraded and abused by captors who have reminded us of the depths to which human depravity can plunge. Now their innocent faces can be seen across London, and hopefully soon the whole of Britain.

Campaign Against Antisemitism has mobilised quickly to put the faces of those taken into captivity where nobody can fail to see them. We know the British public has a strong sense of right and wrong. We must keep these innocent victims and their cause alive, even in an age in which the attention of social media is so quickly diverted, and when traditional media is desperately searching, as it always does when it comes to Israel, for alternative objects of sympathy.

As a grassroots organisation, our first reaction is always to try to empower those who wish to make their own contribution. That is why we have provided support to individuals — especially in the Israeli expatriate community — who are running leafleting campaigns to raise awareness.

Posters featuring the names and faces of the victims have begun appearing on our streets, and you likely will have seen videos of people inhumanely defacing them or tearing them down. We are taking action. If crimes are committed, we report the suspects to the police. Where no crime is committed, we are writing to employers or other associates: we must know whether those close to these suspects share their grotesque values. Where the authorities fail to act, we will. Ripping the faces of infants from a wall is cowardly. It will not deter us.

We have also launched a billboard campaign with the names and faces of some of the youngest captives. Pedestrians, drivers, shoppers, workers and all Londoners will come to know them, as will our politicians and opinion-shapers. These digital billboards cannot be torn down. Much as a frighteningly large segment of people in this country want to prevent British people from seeing these faces, we will not let them.

We have also arranged for digital vans displaying the same images to drive around the capital day after day to raise awareness and force our society to look directly at the impact of evil. Our vans are passing and stopping at major landmarks and centres of power, but also the embassies of nations such as Iran and Qatar, whose support and sympathy for Hamas are well known, as well as the world headquarters of the International Red Cross, whose responsibility it is to care for the welfare of these hostages.

The only “two sides” of the issue are good and evil. Israelis know this. The Jewish community knows this. The British government seems to know it as well. It is time the British public and the media that it watches on television, listens to on the radio and reads in the newspapers finally comes to understand it as well.

We have already identified many of those who support or defend these atrocities and reported them. If the police do not take action, we will pursue them through the courts. Our message to those who promote or excuse antisemitic barbarism is the same as ever: We will do whatever it takes to defend our Jewish community.

If you are concerned that the authorities or employers are failing to act appropriately in a situation that you are aware of, email us in confidence at investigations@antisemitism.org

Gideon Falter is chief executive of Campaign Against Antisemitism