Rating: 5 stars

Good job

Rating: 5 stars

The second parameter from function register_taxonomy() can also be an array. So I modified the script on line 55:

// Only modify user taxonomies, everything else can stay as is
if(is_array($object)) {
    if(!in_array('user', $object)) return;
} else {
    if($object != 'user') return;
}

Rating: 5 stars

Really nice plugin! I modified it a little bit to accommodate multiple selection.

1. Replaced the radiobutton field with following checkbox as shown below

<input type="checkbox" name="<?php echo $key ?>[]" id="<?php echo "{$key}-{$term->slug}" ?>" value="<?php echo $term->slug ?>" <?php checked(true, is_object_in_term($user->ID, $key, $term)) ?> />

2. Updated save_profile function as shown below

$terms = (array) $_POST[$key];
wp_set_object_terms($user_id, $terms, $key, false);

I love this plugin!