Well, as sheisty as it is, they work at Walmart making crap wages. Let them have it. Of all the companies to get screwed by it's own employees, Walmart probably has it coming the most.
Really? Walmart pays market wages, and benefits. Nobody is forced to work at Walmart, people do so by choice, and most are thankful to have employment in a comfortable environment.
If the employees are buying it before it hits the shelves to sell it on the secondary market they are breaking company policy, and quite possibly breaking local and/or state laws. They should be outed, and disciplined, including being fired and/or prosecuted.