I can't tell if it's Flash or Javascript that they were using, but it basically caused my sysetm to lockup until I closed that one page.  Is this proof enough that Wal-mart is evil? :)

I've never seen that before, it's weird how certain things mask themselves as high CPU usage with Xorg, unless it is some kind of weird Xorg problem but I believe it's more of a Flash/Javascript issue from Firefox in Wal-mart's evil scripting.