When you pick up that new Kindle Fire HD this fall, one of the first things you'll notice is an updated version of Amazon's Silk web browser with a Trending Now section. It's a clever trick that takes advantage of Silk's server-based caching to find out what sites are popular among owners. That sounds good on the surface, but it doesn't take much effort to realize that there are privacy concerns already in the air -- Amazon is sharing personal web habits with a wider audience, after
