On July 1st, 2015, it will be illegal to sell a smartphone in Minnesota without antitheft software preinstalled. That's because Minnesota Governor Mark Dayton just signed the first so-called "kill switch" bill into law. The idea is that if smartphone owners can always remotely disable and wipe their phones after they're stolen, it will deter criminals from stealing them at all. It's a feature that police departments across the country have requested, due to how popular it has become for thieves to snatch the small, high-value devices. Nationally, an estimated one in three robberies involves smartphones, according to the FCC.

Strangely, the actual text of Minnesota's "kill switch" bill doesn't actually require a kill switch at all. The letter of the law simply states that phones be "equipped with preloaded antitheft functionality or be capable of downloading that functionality," without specifying what "antitheft" means or what sorts of protections the software might actually offer.

However, that might be a moot point: nearly every major player in the smartphone industry has already promised to offer remote lock and remote wipe functionality by next July. Minnesota's law and other legislation like it are simply codifying what smartphone manufacturers and US cellular carriers are already working towards. The law gives those companies until January 2015 to explain how antitheft software will help.

Minnesota's law also criminalizes buying used phones for cash, though, or even selling them without complying with new recordkeeping requirements. Used phone vendors will need to set up security cameras and take down driver's license numbers for trade-ins, or risk running afoul of the new law.

That doesn't make the cellular industry particularly happy. The CTIA Wireless Association has repeatedly argued that smartphone antitheft laws are unnecessary, due to existing software like Find My iPhone and Android Device Manager, as well as stolen smartphone databases.