I just had a lovely (it was not lovely) experience talking with Telstra about how they knowingly violate privacy when their computers link accounts together. Here’s how you can enjoy this, too:

  1. Buy a new iPad SIM card (the $30 with 3GB of bonus data works nicely).
  2. Activate it online, providing Telstra with your name and an email address (we’ll call this Email A).
  3. Receive an “Activation in progress” email from Telstra, to Email A.
  4. A little time later, receive an “Activation Complete” email from Telstra, to Email B – Email B is an address that either belongs to someone else entirely, or an old/inactive Telstra account that belongs to you.
  5. Observe how Telstra have matched one (new) account to another (old, or belonging to someone else) account based on nothing more than your name.

I assume you could then use this new association between the accounts to then reset the password on the old/belonging to someone else account.