in the real world we must had an identity to make sure that you are exist, usually it is represented by ID card published by government like ID card or pasport , in the cyber world an account on big service provider can be notified that your are exist.
until the end of year the account of my self are:
email address account on gmail : adijaya
Website / Domain Name : adijaya.com, adijaya.org and adijaya.net