How? By constantly downloading the entire database of every application to your local drive? Where it would not only take up space, but could be modified to all

How? By constantly downloading the entire database of every application to your local drive? Where it would not only take up space, but could be modified to allow anything in? Yes, and no. http://news.ycombinator.com/item?id=4427416 http://news.ycombinator.com/item?id=4427416 (besides, if you can just tamper with the filesystem you're kinda in already)