A growing list of U.S. cities are suing Hyundai and Kia over thefts of some models because they say the carmakers haven’t done enough to help owners secure them.

The moves come after about two dozen attorneys general sent Hyundai and Kia a letter urging them to take more action on the matter. They said the carmakers were among the few that didn’t make antitheft technology known as engine immobilizers standard in their U.S.-sold 2011 to 2022 models.

Now multiple large cities have taken that a step further by suing the brands over the issue. St. Louis, Cleveland, San Diego, Milwaukee, Seattle and Columbus, Ohio have all taken legal action.

Parties seeking more from Hyundai and Kia to help owners of the unprotected models say theft of the vehicles has increased dramatically in the past several years. They point to how-to videos posted on social media by thieves instructing others on how to steal the models.

Hyundai and Kia have said they’ve offered owners of the models in question a software upgrade to extend the length of alarms and to require a key be in the ignition in order to start the vehicles. They’ve also sent steering wheel locks to law enforcement agencies to distribute to vehicle owners. The coalition of attorneys general said the measures don’t go far enough and have asked the carmakers to accelerate the software updates and to provide free alternative protections for models that can’t support it.

“Big corporations like Kia and Hyundai must be held accountable for endangering our residents and putting profit over people,” said St. Louis Mayor Tishaura O. Jones in a statement on that city’s lawsuit. “St. Louisans should not be forced to bear the cost of their negligence.”

LEARN MORE: AGs Urge Hyundai Kia to Do More About Car Thefts