I'm a bit late with this one, but it's worth including anyway. Apparently Comet Systems, who produce a free piece of software to change a PC's cursor into something a little more exciting, has secretly been tracking the usage of the product from site to site. Over 60,000 web sites use the software, so Comet are in an excellent position to collate saleable demographics, especially since many of the sites are aimed towards kids, who are worth millions to the marketing people in some of the big toy companies. It's not a big privacy invasion like some are making out, but companies need to be upfront about what they are collecting and tracking.