California isn't technically the first state to enact a kill switch measure; that honor belongs to Minnesota. However, the combination of a large population and an important role in the tech world will make this law tougher to ignore, since phone makers risk giving up a huge potential audience if they flout regulations. There isn't much danger of that happening when most major brands have already embraced the technology, but this should keep any stragglers in line. Is it a good idea? That's a tougher call -- while studies suggest that mandatory kill switches could save money by deterring crooks, there are concerns that the requirement could both hinder progress in anti-theft systems and complicate any phone launches. It's too late to back out, so we'll just have to see how this safeguard works in practice.