Lawmakers in California plan to propose a first-in-the-nation requirement that smartphones and tablets have “kill switches” to be used in case of theft, according to reports.

State Sen. Mark Leno (D-San Francisco) plans to introduce a bill that would require all such devices to include some kind of feature that allows remote disabling by Jan. 1, 2015. San Francisco District Attorney George Gascon, and Los Angeles Mayor Eric Garcetti and Police Chief Charlie Beck all back the measure, which proponents argue would eliminate the black-market value of smartphones.

If a state as large as California passes the bill, it’s very possible it could become a de facto nationwide standard. At the end of December, Minnesota Sen. Amy Klobuchar (D) called on industry to embrace a self-imposed ‘kill switch’ standard after high-profile thefts in her state. And, in November, 31 state attorneys general pushed for the same. In large cities, such as New York or Washington, D.C., roughly 40 percent of all thefts now involve smartphones. More than half of thefts in San Francisco now involve a mobile device, the city District Attorney’s office told the Associated Press.

According to a study of 2011 data by mobile security firm Lookout, the cities where residents are most likely to lose their phones are, in order: Philadelphia, Seattle, Oakland, Ca., Long Beach, Ca., Newark, Detroit, Cleveland, Baltimore, New York and Boston. In Philadelphia and Seattle, residents lost smartphones an average of twice a year.

Industry and some consumers have voiced concerns that the feature could open doors to hackers or the government taking control of the devices.