Indeed it is. A very nasty game. And now there are news reports of such bestial activity being dubbed 'Knockout,' the object of which is to render some random passer-by unconscious with a single punch. A suitable victim seems to be old, frail, female, weak. Cowardly attacks aren't generally made on WWE wrestlers or nightclub bouncers. I’ve seen video footage of such alleged attacks: one member of a gang leaps out from behind his mates and sucker punches some unsuspecting member of the public, and the gang wanders off.
Knockout differs from 'Happy Slapping,' in which, according to the Urban Dictionary, "...chavs ambush an innocent passer-by, and beat them up while one of the gang videos the whole episode on their mobile phone. The video is kept as a trophy and passed round the class at school." Multiple attackers; sustained attack.
The Urban Dictionary also notes of Happy Slapping that, "In America we call this practice assault and I do believe you would get shot with a gun if you tried it."
There is a story circulating on social media regarding Knockout that a victim shot and killed two of a gang when she was assaulted. It gets a lot of, "The punks deserved it" comments on forums, but the story seems to be a work of fiction or wishful thinking. This is not to say that deadly retailiation to a Knockout assault hasn't or won't occur. One day, a victim will pull out a firearm and render the entire gang dead or injured. Or he’ll fail to fall over and there’ll be a frenzied street brawl. It’s only a matter of time.
I pulled the picture at the top of this post from a Facebook post. At a hypothetical level I concur with the sentiment, “Don’t mess with me, or I’ll use deadly force,” but in the Real World things are a lot more complicated.
My concern is how the courts would deal with such a reaction. The initial blow is straightforward Felonious Assault, there’s an obvious aggressor, and there’s a clear victim. Hopefully, CCTV images will bring the perps to justice. But any less-than-instant reaction by the victim is, unfortunately, difficult to justify on the grounds of self-defence. It’s impractical and obviously illegal to be proactively violent towards every gang of youths. It’s difficult to react immediately in the split-second of a single-blow attack. And reacting afterwards isn’t self defence, but revenge.
When the aggressor and his gang walk away, there’s no follow-up violence or explicit threat. So a wronged victim who shoots his assailant (presumably in the back) becomes the new aggressor. Perhaps a solution is to get the gang member responsible to turn around, plug him in his chest and forehead, and then claim to the police that he was coming back to inflict more violence. Good luck with trying that when you're dazed following a knockout blow.
In 2008 in High Wycombe, UK, a British businessman Munir Hussain and his family were threatened in their home by a gang of intruders. Hussain chased, Walid Salem, one of the intruders from the house and, 'about four Asian men,' according to eyewitnesses, beat Salem with a cricket bat and other implements. The court sentenced Munir Hussain to 30 months in prison for the assault on someone who had, it was claimed in court, threatened to kill the Hussain family in their own home. English law treats Salem’s leaving the house and his subsequent beating as separate incidents. He was no longer an immediate threat to Hussain’s family. The whole case is more complex that my summary. I suggest the References section at the bottom of the Wikipedia article.
I bring up this case to illustrate possible legal consequences of actions by the victim.
My feelings on the subject aren’t entirely theoretical. Many years ago I was walking home from the pub with a few friends. When they nipped into the Chinese takeaway, about four or five local yobs beat me to a pulp. They wanted a fight, which I wouldn’t give them. Mercifully, no weapons were involved.