The horrific murder of a soldier in Woolwich naturally generates a deep sense of shock and disgust. Though they may be motivated by an extremely atavastic ideology, the killers would seem to have an unfortunately strong intuitive grasp of our modern media culture.
This creates dilemmas for broadcasters and newspapers. This is important news, which needs to be reported powerfully on the front pages, and the right responses to prevent such debated everywhere. Censorship is rightly resisted. But there are important editorial choices to be made. The fact that everything is available somewhere on the internet does not absolve editors. There is plenty of stuff out there on extremist jihadi websites that does not get put on TV. There can be little doubt that the media platform to spread the message of hatred, fear and division is an important, central motive for the crime. What can we do about the fact that the need to report the grisly news will give the perpetrators the platform that they crave?
This morning, the Metro , the Guardian  and the Telegraph  all offer headlines which primarily communicate the message of the murderers, so handing them the media megaphone which their crime was designed to create. They also, in print, can seem to give more shape to what seems a rather more rambling and incoherent rant. (None of us can yet know quite the precise balance of extremist ideology or mental illness behind this particular crime).
Perhaps surprisingly, it is the Guardian's front page which comes uncomfortably close to being the poster front which the murderer might have designed for himself, with its headline "You will never be safe". If there were an al-Qaeda version of Alastair Campbell somewhere on the Afghan-Pakistan borders, they would surely also be delighted by how the Telegraph - "An eye for an eye, a tooth for a tooth. We won't stop fighting you until you leave us alone" - and the Metro - "You will never be safe, we will not stop fighting" have got the desired message across.
By contrast, the Mail  - "Blood on his hands, hatred in his eyes" - and the Independent  - "Sickening, deluded and uncomfortable" - chose headlines which editorialise against the killers on their front pages. Both the Times  - "Soldier hacked to death in London terror attack" - and the Daily Star  - "Soldier beheaded on London Street" - are among those to offer headlines which report the news.
In truth, despite yesterday's horror, violent Islamist extremism is considerably less effective than the promoters of its legend would have it, though it has, of course, taken much vigilance across the eight years since the last terrorist attack in London to keep us safe.
Events will always be more powerful than trends. Guardian writers often warn that an alarmist media culture is one reason why fear of crime can rise while levels of violent crime fall. It may, however, be more difficult in future for Guardian columnist Polly Toynbee to regard her own paper as an "honourable exception " to this general rule.
Perhaps it is a shame that no newspaper inverted the lens. As one of the killers told her "we want to start a war in London tonight", the astonishingly brave scout leader Ingrid Loyau-Kennett answered him: "it is only you versus many people. You are going to lose" Could that not have been the stuff of front page headlines too?
Politicians have condemned the murder and called for calm. There was little public appetite for the yobbish antics of the English Defence League in Woolwich last night. Both the EDL and the BNP are in potentially fatal disrepair, so will naturally seek to grasp a lifeline, but academic expert Matthew Goodwin notes how much weaker  the extreme right is today than it was in 2005.
Many millions of decent Londoners feel impotent in the face of such evil, though we know that our city will reject the desire of the killers to "create a war in London", just as we did eight years ago, the last time there was a terrorist atrocity on our streets. But how can we show that? There are calls not to over-react, but that may put too much emphasis on how not to react. We should talk about how to react too. What would be the analogous response to the riots clean up two summers ago?
Many people will donate to Help for Heroes or the Royal British Legion. The Challenge Network, which brings people together in social and voluntary activity, suggests a "peace march" across different faiths and communities. Many British Muslims are thinking, too, about whether, beyond the vociferous condemnation which quickly followed the atrocity, there is a more positive and constructive response to offer too.
The form such responses take will depend on what local in people in Woolwich decide that they want to do. There will be a broader appetite across London to make sure that it is not only the killers who grab the media megaphone. How might the voice of millions who quietly reject the offer of hatred and division make sure that we get a hearing too?