The LA city council voted on a measure to phase out environmentally costly plastic bags over the next 16 months. The reason is quite simple. The Californians use 12 billion plastic bags each year, and recycle only 5 % of them. Although such a measure would threaten employment of workers at plastic bag companies, the positive impacts on landfills, waterways and ocean will more than make up for such losses.
Here is a brief video on "Ban on Plastic Bags in LA, What does it Mean?"
Reference: Zahniser, David and Abby Sewell, L.A. OKs ban on plastic bags at checkout, Los Angeles Times, May 24, 2012