Google's Social Graph API and its privacy concerns!

Most of the techies tend to argue a lot about privacy when it comes to Google's services (as they maintain a history of all that u do on web). To add to it, Google has released a new service called Social Graph API few months ago

The main objective of this service is to scan the web and link the public profiles of ur friends. It looks for all your profile URLs (blogger profile, orkut profile, twitter, etc) that are interconnected. It also looks for publicly declared connections between people. For example, if I have linked to X's blog, it will give X all my profile URLs (which I dont).