You'll find the whole story, called "The Cookie Crumbles," written up by Kurt Soller in Newsweek. He raises the important points that Internet sales are not necessarily safer than knocking on strangers' doors, and that a little entrepreneurship should probably be rewarded rather than slapped down, especially in a world where kids will need to know how to use the Internet (at least until the Next Big Thing comes along).
Another point that didn't get raised in the article, which may also underlie the unease with Internet sales, is that the girl in question had her parents' help in setting up the website, and not all Girl Scouts have that opportunity. That's a little troubling, but hardly new. I remember being irked as a kid when other parents took the cookies to work and sold them, while my dad worked at home and had no office to peddle sweets at. Here's hoping the Girl Scouts find a way to make this a "teaching moment" about Internet usage for all concerned, rather than get into an impossible enforcement effort.
And while we're on the topic, when is a major nonprofit going to come up with healthier snacks to sell?