With respect I think we're looking at quite a serious problem here. We have a cadre of youths who have been delinquents for as long as they have been adolescents, thanks to appalling (or non-existent) parenting and a complete lack of drive or aspiration, which has itself been fuelled by a complete con of a schooling system that is only interested in inflating results, not actually educating people academically, let alone teaching them about responsibilities.
And now that delinquent cadre has just worked out that instead of hanging around in groups of six or seven to steal phones, bikes, etc., they can actually use social media to do it in groups of two hundred and get what they like. It's the same problem we've been ignoring for years, it just suddenly got bigger.
If that's right, the problem is serious because it is generational. Afraid to say that heavy-handed policing is probably needed in the short term to spoil the party, followed by some serious stints of community service with an extensive social rehabilitation element.