Starting in July 2015, every smartphone sold in the state of California will be required to have a feature known as a kill switch, which allows smartphone users to remotely wipe the contents of their phones and make them unusable in case they get stolen.

California Governor Jerry Brown on Monday signed the bill, making California the first state to require the remote wipe option be automatically turned on in all new smartphones. (Earlier this year, Minnesota became the first state to require phones to have the ability, but the rule doesn't explicitly state that the software must be turned on.) Supporters say that including a kill switch on every phone can discourage smartphone theft, because it makes stolen phones useless to thieves.

So what could change about your phone if it gets a kill switch? Possibly not that much. In fact, many smartphone owners already have the capability to meet California's standards -- no waiting or residency in the Golden State required.

Apple currently lets users do this with the "Find my iPhone" app, which lets you track your iPhone and also delete data from iPhones, tablets and computers. The app is linked to your iCloud account, so you can log in from anywhere via or through apps on your devices.

Using "Find my iPhone" also automatically kicks on Apple's activation lock for phones running its latest operating system. That setting requires users to enter their iCloud usernames and password  to disable the tracking software, sign out of iCloud or erase and reactivate your phone -- all things thieves would definitely want to do to resell the phone.

Bloomberg reported in June that iPhone thefts have dropped since Apple introduced this "kill switch" type feature in September. But the feature also carries some caveats. Namely, users have to be extra mindful to create strong passwords for the accounts that control these software features, since an aggressive hack could make you lose access to your own phone.

Samsung also has its own security measures to prevent phones from being reset in case they're stolen or lost. Called  "Reactivation Lock," the feature does more or less the same thing as the iPhone app, though it's tied instead to your Samsung account. Turning on the feature prevents whoever has your phone from performing a factory reset wipe or from recovering your Android data after resetting.

Between Apple and Samsung, that means at least 68 percent of U.S. smartphones already have something akin to the "kill switch" capability. And that number is only expected to grow: Google and Microsoft have also announced plans to put these kinds of features in their Android and Windows Phone systems. Doing so would essentially offer the option to all smartphone buyers, regardless of what state laws require.