evidence: Grocery store shelves across America are wiped clean, and they’re staying empty as stores struggle to quickly restock everyday necessities such as milk, bread, meat, canned soups and cleaning products. Disgruntled shoppers have unleashed their frustration on social media over the last several days, posting photos on Twitter of bare shelves at Trader Joe’s locations, Giant Foods and Publix stores, among many others. [...] At Trader Joe’s stores, shoppers over the weekend saw messages attached to empty shelves blaming weather emergencies for delivery delays.