It doesn't have anything to do with WalMart per se. Prices are rising faster than retailers can keep up with changing the shelf tags. I've seen this at Macy's and Target as well. It stinks, but to demonize one place when a lot of them are unable to keep up with rapid inflation isn't right either. And someone putting an unauthorized purchase from WM on your credit card isn't actually their fault either... the person whole stole your card number could have ordered from the local pizza joint or Bloomingdale's.
Oooooo, I'm not buying that. It does make me laugh when, say, a grocer will say, "Oh, that can of peas has gone up 20%, we must pass the price increase on RIGHT NOW", when we all know they have a stock of those peas in the back, and further down the supply chain in warehouses etc., that they didn't pay the new price on. Then we're supposed to believe that there's such a scarcity of low paid staff, they simply don't have time to change a price ticket on a shelf? Really?
This is why we need stupid laws. It is the stores responsibility to let the customer know how much a product they're offering, costs. It's such a basic part of their service. Stores compete on price, the entire market and our choice of where to shop is predicated on comparing price A with price B. Yet now it's not possible? Surely not.
When I was a young adult, I had a job stocking shelves at a large supermarket (Tesco) at night (22:00 to 6:00). In that job, you get assigned two or three aisles, and you have to restock it and make it look tidy. If there were price changes, you'd make those changes too. So, there is a run through of every item and price each 24 hour cycle. Prices are changing quickly, but not that quickly. Since the consumer cannot possibly know the price of the item and if it's changed, surely the sole responsibility to let us know is the store?