Google, Yahoo, Microsoft's Bing, and other leading websites are leaking medical histories, family income, search queries, and massive amounts of other sensitive data that can be intercepted even when encrypted, computer scientists revealed in a new research paper.
Researchers from Indiana University and Microsoft itself were able to infer the sensitive data by analyzing the distinct size and other attributes of each exchange between a user and the website she was interacting with. Using man-in-the-middle attacks, they could glean the information even when transactions were encrypted using the Secure Sockets Layer, or SSL, protocol or the WPA, or Wi-fi Protected Access protocol.
Interesting article here:

http://www.theregister.co.uk/2010/03...acks_web_apps/