CNET reports on the continuing battle between the hand wringing privacy advocates and those companies seeking to invent new ways of better targeting ads and products to individuals. This time, advocates are voicing concern about an Amazon.com patent on the idea of using users' own written product reviews, among other things, to parse out useful information for future targeting. Also in the cross-hairs is technology used to guess information about users based on the types of products they buy or give others. Especially when the guesses involve children - apparently a new third rail for marketers - some find the methods troubling. "There's no guarantee that there won't be some disastrous privacy invasion coming out of this," one advocate told CNET.