If there's one constant in the online universe, it's that search engines and other web services are gathering more and more information on us, reports the BBC.

Search engines from Google to Yahoo to MSN, and even individual sites, track what we do online and build profiles of us based on that behavior. This worries privacy advocates, who feel we are no longer able to keep our activities to ourselves under such intimate surveillance.

The companies doing the tracking, though, claim it's all about providing a more relevant experience for users.

There's also the advertising aspect. By painting a user picture based on search, e-commerce and other online habits, ads from major ad vendors can be better targeted. This provides a more relevant ad experience to the user and therefore more value to the advertiser and vendor, who can charge a premium rate for access to desired demographics.

One expert says that as a culture we will come to terms with this close behavioral scrutiny within five years. By then, he speculates, technologies will exist to empower people to choose the extent to which they wish to be identified.

Until then, it's incumbent on the user to be mindful of what their online self-portrait looks like, click by telling click.