The age of Big Brother everywhere is certainly upon us, and while we've seen (or at least heard of) tracking devices being implanted in the most unusual of places, it looks like Xerox is hoping to join the devilish fray. In an attempt to craft a demographic extractor to garner marketing dollars galore, a recently filed patent application spells out a system that utilizes software (and potentially hardware) to map users to "centroid vectors" which would determine a person's age, sex, and other "private" information simply based on their website visits. Interestingly, test cases are reportedly showing a respectable "75-percent accuracy rate" so long as a "sufficient number of pages were visited." Still, we can't imagine any tracing technology would be lawfully allowed behind the backs of law-abiding citizens (right?), but considering that even your TiVo has the potential to sell your soul to lucrative ad agencies, we wouldn't put it past 'em.