Why Didn't You Call?

At the checkout line in Walmart today, I saw taped to the bottom of the check writing platform, a handwritten, photocopied notice that read,

Until further notice, all pre-paid phone cards and phone cards are not to be sold.

Or, something like that. I asked the clerk why, and she didn't know. In fact, she told me that no one else knew either. Well, I just looked it up, and I assume that it's a perfunctory action by Walmart so that they will become liable for knowingly sell "fraudulent product:"

http://ap.google.com/article/ALeqM5iH-CI2-V9Emibx-qk35jXz-i3ANwD93E19F00