You can change default user profile icon URLs. One of the example could be checking if user is VIP user changing icon to something else if user is banned change the icon to banned ICON.

function my_component_init(){
ossn_add_hook('user', 'icon:urls', 'my_component_hook');
function my_component_hook($hook, $type, $urlsObj, $instance){
//$urlsObj contain $urlsObj->iconURLS
//$instance contain user instance
error_log(print_r($urlsObj, true));
return $urlsObj;
ossn_register_callback('ossn', 'init', 'my_component_init');

User profile icon URL