While the existence of this kind of media and its gravity hasn't been ignored before now, the new guidelines clarify their importance to courts faced with relevant cases -- though it's just one consideration among many, including the nature of the offence and age of offender. The potential aggravating factor is described as:
"Deliberate humiliation of victim, including but not limited to filming of the offence, deliberately committing the offence before a group of peers with the intent of causing additional distress or circulating details/photos/videos etc of the offence on social media or within peer groups."
It has been added to the non-exhaustive list of factors that should be considered when sentencing youths for both general and sexual offences, with guidelines for the latter class now also including a mention of online grooming, where that has played a role. Sentencing guidelines for adults in England and Wales don't cite social media specifically yet -- though there are similar aggravating factors to do with capturing and disseminated media related to offences -- but it's understandable why the Sentencing Council would make it a priority in more comprehensive guidelines for young offenders.
The sad fact is: online bragging of this kind, particularly on social networks, is all too common. In a recent, serious UK case, two 15-year old girls were given life sentences for beating and ultimately murdering a woman in her home. They documented the attack on Snapchat. An woman in the US was also accused last month of broadcasting her friend's rape live, over Periscope.
Slowly but surely, law enforcement agencies are exploring the role the internet and social networks play in both minor offences and serious crimes. On the other side of the desk, for example, the UK's Crown Prosecution service updated its Social Media Guidelines a few months ago to give criminal prosecutors a better understanding of what constitutes online abuse.
The new sentencing guidelines announced today are still subject to change after a 12-week open consultation period -- and it's important to note that their expansion isn't at all limited to the inclusion of tech-specific aggravating factors -- but there's no reason the social media mentions won't be incorporated when the proposals become official advice.