The phenomenon started in Milwaukee (the "Kia Boys" challenge), and I happen to live in Chicagoland, which experienced a huge wave of carjackings immediately afterwards. I have one of them recorded on my Nest camera in the alley behind my house. Nothing in particular about those two cities otherwise.

As the sibling points out: it's a broader issue than just carjackings --- but the carjackings themselves were novel, scared the shit out of people in a way that stochastic-seeming strong arm robberies don't. The headline here is: it was a gravely negligent thing for Kia to have done; I hope they lose their shirts.