In brief: Kia and its parent company, Hyundai, are being sued by cities across the US for failing to install engine immobilizers in their vehicles. The vulnerability was exposed in viral TikTok and YouTube videos, leading to a spate of car thefts, injuries, and fatalities.

The Kia Challenge trend started circulating on social media in the middle of 2021. The clips show how it's possible to remove the steering column covering on some 2010-2020 Hyundai and Kia vehicles, revealing a slot that fits a USB Type-A plug. Turning the plug using a standard USB cable activates the ignition as the cars lack an immobilizer. Only vehicles that use a mechanical key rather than press-to-start ignition systems are susceptible to the technique.

Motherboard reports that Seattle, Baltimore, Cleveland, New York, Chicago, St. Louis, and Columbus have all sued Kia and Hyundai since the start of the year for not including immobilizers on their vehicles, making them easy to steal.

In a lawsuit filed last week by the City of Chicago, it was revealed that more than 8,800 Kia and Hyundai vehicles were stolen in the city throughout 2022, making up 41% of all car thefts. That figure has climbed to over 50% this year.

It's the same story in other cities, many of which have seen the number of Kia and Hyundai thefts increase by three-digit percentages. It's been especially bad in Milwaukee, regarded as the center of the Kia Boyz trend, which in June 2021 saw thefts of these vehicles increase 2,500% year-on-year.

In February, the United States National Highway Traffic Safety Administration (NHTSA) announced that the Kia challenge had been responsible for 14 reported crashes and eight fatalities.

In June, 18 state attorneys general asked for a recall of the cars, but the NHTSA said it had not determined that this issue constitutes either a safety defect or noncompliance requiring a recall.

Hyundai and Kia started rolling out free software updates earlier this year - installed via a dealer - that require the key to be in the ignition switch to start affected models. But just 650,000 vehicles have gotten the software update, out of three million in total. There have also been more than 190,000 wheel locks distributed.

In May, Hyundai and Kia agreed to pay $200 million to settle a consumer class-action lawsuit relating to the thefts.

More cities will likely join those suing Kia and Hyundai, lawsuits that the companies says are "without merit." Both automakers now include immobilizers on their new cars.