My cell phone provider gave away my phone number to another one of their customers so I got a new one when I updated my account which had been dormant for 3 months. I then tried to logon to coinbase but they wanted sms authentication. So I selected that my phone number changed when I attempted to login, so they forwarded me to AUTHY's web site to change my sms cell phone number to my new cell phone number. AUTHY claims it must do a four day investigation before changing the sms cell phone number. On day 3 I received an sms to my new phone number from AUTHY trying to validate the change. Less than 30 seconds later I received a phone call from some stranger using my old cell number. How did they get my new cell phone number? I believe AUTHY gave it to them in their investigation. I didn't sign any agreement with coinbase or AUTHY to give out my phone number to strangers!