public function getActivatedPhoneNumbers()
    {
        Piwik::checkUserIsNotAnonymous();

        $phoneNumbers = $this->retrievePhoneNumbers();

        $activatedPhoneNumbers = array();
        foreach ($phoneNumbers as $phoneNumber => $verificationCode) {
            if (self::isActivated($verificationCode)) {
                $activatedPhoneNumbers[] = $phoneNumber;
            }
        }

        return $activatedPhoneNumbers;
    }