The government has launched a series of hard-hitting adverts, featuring gruesome images of mutilated hands and knives sticking out of victims’ chests.

But even these fail to truly capture the real horror of what knives can do and the trauma it can cause. I know from first hand experience.

On July 23, 2000, I was returning home from a night out with a friend in Brixton in south London.

As were walking down a busy a street, a figure emerged from a side road with his arms in the air, wailing for help. At first we thought he was drunk, but as we got closer we could see he had blood on his hands and was in extreme distress.

“My friend has been stabbed”, he cried out through sobs.

About 20 yards on the side street, we could see his friend — outstretched wearing a T-shirt and shorts lying on the floor in a pool of blood.

I hailed down a passing taxi and told the occupants to call for help while my friend, a doctor, did his best to resuscitate the victim.

But it was far too late. The man died within minutes and I can still remember his last, gurgled breath.

He had received two wounds — one to his knee and the fatal one through his belly, with the layers of subcutaneous fat clearly on display. The knife had passed through his spleen, heart and lungs. He hadn’t stood a chance.

It is hard to describe the horror of the scene. The road underneath the young man’s body was dark and there was blood sprayed all over a nearby wall. His two friends, one of whom had also been stabbed, were drenched in blood and numbed with shock.

They could barely speak when a flustered police officer finally arrived.

And what had led to this? They weren’t members of a gang — in fact they were students from Canada who had come to Britain for their studies.

It transpired that one of the three friends had been mugged earlier in the night, the robbers taking his wallet with 60 pounds. When he went home and told his housemates, they went to try and get his wallet back, and confronted the robbers.

It was a decision that was to prove fatal for one of them.

The killer, another young man, was tracked down soon afterwards and given a life sentence for the murder. That moment of violence had ruined his life as well.

Mayor Boris Johnson’s ban on drinking alcohol on the London underground starts on Sunday.The news hasn’t gone down well in some quarters and plenty of groups on Facebook have said they will be holding protest wakes.

Others believe the ban will have little effect on threatening behaviour on the tube anyway — most people who cause problems are drunk anyway and only a few are actually carrying cans with them, they say.

Do you believe the ban will make much difference?

A policeman’s lot is not a happy one, sing the officers in Gilbert and Sullivan’s “The Pirates of Penzance”.

Judging from views expressed by many delegates who gathered in Bournemouth for the Police Federation’s annual conference, it is a refrain that is appropriate for Britain’s bobbies today.

From anger over pay and talk of possible strikes, to underlying resentment about the growth in the number of community support officers, rank and file police are far from content.

“The sergeants of England and Wales are not happy,” said Paul McKeever, chairman of the Federation’s sergeant committee, as he began his speech before delivering a damning verdict of Prime Minister Gordon Brown’s government.

Brown was a “Mr Bean” figure he said, borrowing the scathing reference from Lib Dem MP Vince Cable, a “bean counter” who had broken the trust between government and police officers over the decision not to backdate a pay rise recommended by an independent panel as expected.

“How feckless, how incompetent and how very imprudent Gordon Brown must have been to get us into this dreadful state, McKeever went on, before reminding his colleagues that Brown has registered the fastest fall in popularity of any British Prime Minister.

It was hardly surprising that Home Secretary Jacqui Smith bore the brunt of the resentment over pay when she faced the delegates. A brave decision, said Jan Berry, the Federation’s chairman, but not one that spared her from ridicule or mockery.

But it wasn’t just pay that had got the delegates’ heckles up. The growth in the number of community support officers (PCSOs) — officers who have less training and fewer powers than full police officers — was another issue arousing strong feeling.

Smith was greeted with jeering and laughter when she suggested that the public would be as happy to have a PCSO as a proper bobby on the beat. Berry said her members feared that it could mean proper officers only dealt with confrontational issues, “a paramilitary force and one fundamentally different from the concept of policing by consent”.

Berry continued: “The inept management of modernisation is nothing short of a scandal.”

Despite the anger directed at the government, perhaps the recipient of the greatest derision was Richard Bobbett, the Chief Executive Officer for Airwave, the police’s radio communications system.

It often didn’t work properly in London, didn’t work at all in the Millennium Stadium in Cardiff — just making a “beep, beep” noise, and radios needed to be put in plastic bags if it was raining, delegates told him.

Alan Gordon, Police Federation vice chairman, said he suspected it would struggle to even cope with “a well-attended village egg and spoon race”.

The problem of yobs causing misery for their neighbours and local communities is a daily reality for many people.

Be it from gangs of drunken teenagers to more serious cases of vandalism, assaults or even murder, stories of problems involving young louts are rarely out of the newspapers.

However, coming up with an effective plan to deal with the troublemakers has proved difficult for politicians, police and local officials.

Anti-social behaviour orders (ASBOs) have probably been the best-known antidote the authorities have used. But experts say these have their limits and some serial offenders just view them as a “badge of honour”.

The latest initiative to get the backing of the government is a scheme to turn the tables on the yobs with the police hounding them to make their lives uncomfortable.

Residents in Essex, where the Operation Leopard idea was first introduced, say it was a great success.

But it is likely to alarm some civil rights groups, who have expressed concern about the use of ASBOs.

Is it time to get tough on those who refuse to abide by the rules the rest of us adhere to? Or is this just a headline-grabbing announcement? Send us your comments

A senior detective has questioned the effectiveness of CCTV, saying it helps solve only a tiny minority of street crimes and that its use has been an “utter fiasco”.

Detective Chief Inspector Mick Neville, head of the Metropolitan police’s division on visual images, identifications and detections, wants better training for police officers in using CCTV, more sophisticated technology and a national database to allow offenders to be tracked and identified.

Britain is the surveillance capital of the world, with one camera for every 14 people according to civil rights groups, and billions of pounds has been spent on setting up systems.

Last year the Home Office, which has ploughed millions into CCTV projects, itself questioned the effectiveness of some systems as the footage they provided was not good enough to be used as evidence in court.

CCTV has always proved to be a divisive issue with some people believing they represent the growth of a “Big Brother” society. However, many communities have welcomed them with open arms, hoping they will deter criminals and vandals.

Are the cameras a waste of money and an infringement of civil liberties? Or are they a vital deterrent? Send us your comments.

Ofcom says millions of children who use social networking sites are exposing themselves to potential danger by leaving their privacy settings on “open,” thereby allowing all and sundry to peruse their personal details.

Its figures show a no less than a quarter of all children aged 8 to 11 in Britain, are registered with a social networking site.

It is the latest in a long series of warnings about Internet danger to children — which may suggest that either the children or their parents do not seem to care too much.

Do you think users are being too blasé, or are the dangers being exaggerated? Have you ever had any personal experience of the dangers Ofcom and others warn us about?

Two initiatives have focused the mind on badly behaved children this week and how to deal with them.

Under the first, Children’s Secretary Ed Balls proposes that trouble-makers as young as 10 should sign a good behaviour contract . The “most challenging” among them will have to stick to the order or risk a criminal record.

The second, more extreme, suggestion comes from Gary Pugh, forensic science director for the Metropolitan Police, who was quoted in The Observer as saying trouble makers as young as five should be recorded on the national DNA database because future offenders can be picked out an early age.

The idea has been widely criticised, both by those who dislike the idea of stigmatising children at such a young age and those who bemoan what they call the government’s obsession with compiling databases — and its embarrassing tendency to lose personal data. The government has been non-committal but says it is listening to all views.

Do you believe law enforcement authorities need more tools at their disposal to deal with unruly children?