With the help of the California Rifle and Pistol Association, four people are suing the state's attorney general and Los Angeles County's sheriff over a set of restrictive policies that combine, they argue, to rob them of their Second Amendment rights.
Flanagan v. Harris challenges the fact that California heavily limits the open carry of firearms, and L.A. County makes concealed carry very difficult as well. Together, the suit states, those state and local policies mean "the vast majority of the population…cannot obtain a license to publicly carry a firearm."
A recent federal case in the 9th Circuit Court of Appeals, Peruta, upheld restrictions similar to Los Angeles' and concluded that concealed carry was definitely not protected by the Second Amendment, in that court's opinion. The precedent, which covers California, will likely make winning Flanagan a lot harder, though the Peruta decision acknowledges that the open-carry question remains undecided.
Flanagan's plaintiffs hope to establish that the Constitution does protect a right to carry a gun for self-defense in public in some manner, whether concealed or open. Lower courts have offered contradictory answers to that question, making this ripe for eventually appearing before the Supreme Court.