Change location of Opt-in/out checkbox on User Account Edit to "Analytics & Tracking" vertical tab like Google Analytics

Starting with line 301 of piwik.module, you will find the code for the tracking option:

/**
* Implement hook_form_FORM_ID_alter().
*
* Allow users to decide if tracking code will be added to pages or not.
*/
function piwik_form_user_profile_form_alter(&$form, &$form_state) {
$account = $form['#user'];
$category = $form['#user_category'];

if ($category == 'account' && user_access('opt-in or out of tracking') && ($custom = variable_get('piwik_custom', 0)) != 0 && _piwik_visibility_roles($account)) {
$form['piwik'] = array(
'#type' => 'fieldset',
'#title' => t('Piwik configuration'),
'#weight' => 3,
'#collapsible' => TRUE,
'#tree' => TRUE
);

switch ($custom) {
case 1:
$description = t('Users are tracked by default, but you are able to opt out.');
break;

case 2:
$description = t('Users are not tracked by default, but you are able to opt in.');
break;
}

$form['piwik']['custom'] = array(
'#type' => 'checkbox',
'#title' => t('Enable user tracking'),
'#description' => $description,
'#default_value' => isset($account->data['piwik']['custom']) ? $account->data['piwik']['custom'] : ($custom == 1),
);

return $form;
}
}

So, this isn't in a vertical tab. How can I make it display in the vertical tab I mentioned?