current user CANNOT?

How do I do this...

I want to hide user's email addresses from anybody who is not a network admin..

Is there such a thing as !current_user _can? If not what should I use?

Eg

// prevent subsite admins from seeing user's email addresses.
if ( !current_user_can('manage_network') ) {
add_action('manage_users_columns','remove_user_posts_column');
function remove_user_posts_column($column_headers) {
unset($column_headers['posts']);
return $column_headers;
}

add_action('manage_users_columns','remove_user_email_column');
function remove_user_email_column($column_headers) {
unset($column_headers['email']);
return $column_headers;
}
}

Thanks!