California lawmakers are pushing legislation to reduce theft and increase data privacy for smartphones, tablets, and other mobile devices by mandating that all mobile products sold in the state have a so-called "kill switch."

If the bill passes, all mobile devices sold in California after Jan. 1, 2015 -- no matter what operating system they run -- would have to have kill-switch technology preinstalled at the point of sale.

Kill switches are software programs installed on devices that allow users to deactivate their phone remotely, rendering it useless and locking out thieves from the system, while protecting against potential data theft.

Importantly, kill switches, if ubiquitous, would also discourage smartphone theft in the first place, since it would become common knowledge that a stolen phone was an unusable (and unsellable) phone.

The bill, introduced on Friday by State Sen. Mark Leno (D-San Francisco), and sponsored by San Francisco District Attorney George Gascón, would impose fines of up to $2,500 for each phone sold by companies without a kill switch preinstalled. While the bill would only apply to phones sold in the state of California, if passed, the legislation would likely push smartphone and tablet makers to install the software on all devices sold in the U.S.

With robberies of smartphones reaching an all-time high, California cannot continue to stand by when a solution to the problem is readily available," Senator Leno said in a statement to the New York Times. "Today we are officially stepping in and requiring the cellphone industry to take the necessary steps to curb violent smartphone thefts and protect the safety of the very consumers they rely upon to support their businesses."

Smartphone thefts have reached epidemic levels in major U.S. cities in the past few years. In 2013, 2,400 cellphones were reported stolen in San Francisco alone, which is a 23 percent rise from the previous year. Nationwide, cell phone thefts amount to an average of between 30 and 40 percent of all reported thefts, costing U.S. consumers more than $30 billion in 2012, according to Federal Communications Commission data cited by Gascón and Leno.

The two behind the kill switch bill have met resistance to their ideas before. Last year, Gascón made a proposition for kill switches to be installed to major device manufacturer Samsung, which was interested in the idea, but was ultimately stymied by wireless carriers. Samsung "engaged a third-party developer willing to develop it, and said they would roll it out with the Galaxy 5 phones," said Gascón at the time. "But the carriers said to Samsung, 'Absolutely not.' We were perplexed, so we started to look into it."

The opposition came chiefly from the CTIA -- the trade association of U.S. wireless carriers. The CTIA has argued that kill switches pose "very serious risks," according to PCMag, citing the inability of a disabled device to make emergency phone calls, possibilities for hackers to take advantage of kill switches, and saying it would necessitate users who only temporarily lost their devices to buy a new phone after they hit the kill switch. However, in the case of Apple's Activation Lock, a kill switch that's part of the new iOS 7 operating system, users can still reactivate disabled phones with a correct user name and password.

Leno and Gascón suspect wireless carriers are more concerned with losing profits from insurance programs, which many customers buy to cover cases of lost or stolen smartphones. In any case, the problem of cellphone theft is not going away anytime soon, and neither is the fight over kill switches.