While sites such as Twitter and Facebook make it so easy to communicate with
groups of friends or colleagues online, there's also a serious privacy issue.
Mainly, the lack of it. It's easy to search through the entire posting
history of any user, or merely to check the directory to see if that user has
an account on the system at all. A relatively new system called Cloaklet aims
to change that. It promises total privacy. All of your messages are
encrypted, and the only person that can read them is the person you send them
to.
http://www.techsupportalert.com/content/communicate-online-extra-privacy.htm
