We use email + sms verification at all our boards. Both must clear, otherwise the account won't be activated. The sms verification is done via custom add-on.
In addition we do a manual data check for each new account within the first day of registration. This is also handled by a custom add-on and we can ask the user to upload a personal identification document in case we have doubts the personal data given by him was correct.
We don't accept anonymous registrations at most of our boards.