How to change Akismet commenter privacy notice?

Aha, I finally got it working:

<?php
/*
Plugin Name: Akismet Better Privacy Notice
Description: Inform users about what's actually happening with their data
*/

add_filter (
    'akismet_comment_form_privacy_notice_markup', 'better_display_comment_form_privacy_notice'
);

function better_display_comment_form_privacy_notice() {
    echo sprintf(
        '<p class="akismet_comment_form_privacy_notice">' .
        'Warning: This site uses Akismet to filter spam.' .
        ' Until or unless I can find a suitable replacement anti-spam solution, this means that' .
        ' (per their <a href="%s" target="_blank">indemnification document</a>)' .
        ' <strong>all commenters\' IP addresses will be sent to Automattic, Inc.</strong>,' .
        ' who may choose to share such with 3rd parties.' .
        '<br />If this is unacceptable to you,' .
        ' I highly recommend using an anonymous proxy or public Wi-Fi connection' .
        ' when commenting.' .
        '</p>' ,
        'https://akismet.com/privacy/'
    );
}

?>