Back in 2005, voters in San Francisco approved a ban on handguns via a referendum, though the measure was ultimately struck down by the courts before it could take effect. Since then the city has made a habit of targeting legal gun owners; not only by imposing local ordinances but going after the city’s lone gun store and seeking a ban on gun shows at the Cow Palace in neighboring Daly City.

Now San Francisco is revisiting the idea of a gun ban, only this time instead of banning handguns supervisors have approved an ordinance banning the possession of so-called “ghost guns.”

The Board of Supervisors unanimously voted to approve legislation Tuesday from Supervisor Catherine Stefani that prohibits the sale or possession of ghost guns in The City.

The weapons, bought in parts online that can be put together at home, pose a problem for law enforcement because they lack a serial number which can be traced back to an owner or seller.

They’ve also become the “weapon of choice” for those prohibited from owning firearms, because ghost guns can be purchased without a background check, Stefani said before the vote.

California currently requires the person buying a ghost gun to apply for a serial number with the California Department of Justice and affix the digits to the gun after assembly.

But Stefani said it’s not enough.

“We have to take a step here in San Francisco to say these guns are causing way too much harm in our communities and it’s time that we do something about them,” Stefani said.

The legislation will make possessing or selling a ghost gun in San Francisco a misdemeanor punishable by a fine of up to $1,000 and jail time, with some exceptions.

Actually, the measure goes further than banning completed firearms that are home-built. According to NRA’s Institute for Legislative Action, the new ordinance in San Francisco makes it a crime to possess “materials” that have been “shaped or formed in any way for the purpose of becoming a frame or receiver of a firearm, rifle or shotgun and which may be readily made into a functional frame or receiver through milling, drilling or other means.”

Moreover, the legislation prohibits licensed dealers from transferring those pieces of “material” to private individuals unless they apply for and receive serial numbers from the DoJ and the serial numbers are affixed to the item prior to possession. California law already requires individuals to first apply for and receive serial numbers before assembling a home-built firearm and sets an allotted time for application.

However, California law does not ban the possession of unserialized “materials” lacking the requisite milling to be considered a finished frame or receiver.

In other words, there’s already a ban on “ghost guns” under California state law, since all home-built firearms are required to be registered and serialized with the state’s Department of Justice. I’m sure that there are plenty of criminals in California who aren’t abiding by that law, but that doesn’t justify San Francisco’s new crackdown. The city has already run the last gun store out of town, and now officials are telling residents they’re not allowed to make their own firearms for self-defense either.

The misdemeanor offense isn’t likely to dissuade criminals from acquiring a gun illicitly, but it may very well have a chilling effect on citizens who would like to own a firearm for self-defense and don’t want to spend a day sitting in traffic trying to get to a gun store (two days, actually, given the state’s 10-day waiting period for firearm sales). Of course, given San Francisco’s politics, supervisors likely view that as a feature, not a bug, of their new ordinance.

Police, prosecutors, and politicians have been pointing fingers at each other over San Francisco’s rising crime rate for months now, and this new ordinance allows city supervisors to say they’re “doing something” in response increasing levels of violence. True enough, but “doing something” isn’t the same as doing something that works, as San Francisco residents are about to find out.