This seems like a panacea for tailored advertising or big brother ~ you decided. Ok, so I join/register for a web 2.0 web site (or any web site) and of course I give them my name, address, email, etc. and for fun let's say they grab my browser history. Now they could gather information about me by doing a Google search and of course every time I revisit the site they could re-gather my browser history ~ put all that info into an ever growing database and now you have the ability to tailor advertisements. Come to think of it maybe I should start a site that does this ~ anyone want to help :)