WordPress File wp-admin/includes/user.php

edit_user()

Edit user settings based on contents of $_POST

use_ssl_preference()

Optional SSL preference that can be turned on by hooking to the ‘personal_options’ action.

wp_delete_user()

Remove user and optionally reassign posts and links to another user.

check_passwords

Fires before the password and confirm password fields are checked for congruity.

delete_user

Fires immediately before a user is deleted from the database.