Civil-liberties advocates called the new law that takes effect Jan. 1 an important advance and said it highlights the need for similar protections at the national level.
The California Electronic Communications Privacy Act was signed by Gov. Jerry Brown on Thursday. It's only the third of its kind in the U.S.
While some states guarantee some of its protections, only Maine and Utah previously had comprehensive laws on the books, noted Hanni Fakhoury, senior staff attorney for the Electronic Frontier Foundation.
