Backed by many tech firms and the ACLU, the privacy law hits the books but doesn't apply to federal law enforcement authorities.
Civil liberties advocates welcome the change, but say the public will remain largely unaware if their information has been caught up in criminal investigations.
Should the social network be able to contest a search warrant on behalf of its users? That issue is now being debated in court.
Gov. Jerry Brown vetoes a bill that would have required law enforcement to obtain a warrant before using surveillance drones.
The bill, which is now on the governor's desk, pits privacy advocates against law enforcement interests in managing the emerging technology.
Social network was under a gag order until recently to disclose "by far the largest" search warrant request it's ever received.
The two are the latest to publicly support Microsoft in its protest of a search warrant for customer emails stored abroad.
Feel the fear with a video collection of animal attacks presented in startling slo-mo by BBC Earth.
A federal court of appeals rules that cell phone carriers have no obligation to hand over users' location history without a warrant.
Company says demand for emails stored in Ireland violates foreign sovereignty, erodes trust in US firms. US says it's essential for crime fighting.