Most people use their phone as 2-factor. So if a thief has your phone, 2-factor with a phone is pointless.
8 karma · joined August 15, 2013
As for publishing your phone number so that you can receive bitcoins, you can publish your secondary phone numbers. We only allow you to use SMS to access your account from your primary phone number, but you can receive funds on any other phone number attached to your account. So even if a hacker knows your pin and is able to fake a call to us from your published phone number, they won't have access to your bitcoins.