public function removePhoneNumber($phoneNumber)
    {
        Piwik::checkUserIsNotAnonymous();

        $phoneNumbers = $this->retrievePhoneNumbers();
        unset($phoneNumbers[$phoneNumber]);
        $this->savePhoneNumbers($phoneNumbers);

        /**
         * Triggered after a phone number has been deleted. This event should be used to clean up any data that is
         * related to the now deleted phone number. The ScheduledReports plugin, for example, uses this event to remove
         * the phone number from all reports to make sure no text message will be sent to this phone number.
         *
         * **Example**
         *
         *     public function deletePhoneNumber($phoneNumber)
         *     {
         *         $this->unsubscribePhoneNumberFromScheduledReport($phoneNumber);
         *     }
         *
         * @param string $phoneNumber The phone number that was just deleted.
         */
        Piwik::postEvent('MobileMessaging.deletePhoneNumber', array($phoneNumber));

        return true;
    }