I learned about this earlier today, and I have to say that, even though I work in the legal field, I am thoroughly disgusted by the actions of Walmart. There comes a point in time where morals and doing what is right should come before what you are legally allowed (and not obligated) to do.
Much as I love Walmart, I cannot say that I will be able to shop there again. Hello Zellers!!! (And that has the bonus of being Canadian, eh? lol).