Gavin Newsom signs California bill into law banning all plastic bags at grocery stores KCRA SacramentoCalifornia Bans All Plastic Bags After Its First Effort Backfired The New York TimesCalifornia has officially banned a common grocery store item SFGATEGovernor signs California plastic bag bill into law Los Angeles TimesCalifornia bans all plastic shopping bags at store checkouts: When will it go into effect? USA TODAY