Gun laws vary state by state By: CNBC.com News November 20, 2014 at 08:47 AM EST More companies, many in the food business, are asking customers to keep guns out of stores. A brief history of gun laws and guns in public places. Read More >> Related Stocks: AMC Entertainment Holdings Chipotle Mexican Grill Costco Wholesale Jack IN The Box Inc Kroger Co Sprouts Farmers Market Starbucks Corp Target Corp Whole Foods Market