Does anyone know how facebook is able to track all my friends list? Many of my friends who were on my email account have now signed facebook and they told me that I invited them for free activation? How is that possible, I didnt invite them to join facebook? Also neither did I accept their friendship nor did I send them to add me on their friend list, but I was automatically added in their list? Is this some kind of hack used by facebook, are they playing with our piracy to make their website famous?