bbPress.org

so something like

$user_id = get_current_user_id()  ;
$topic_count  = bbp_get_user_topic_count_raw( $user_id);
$reply_count = bbp_get_user_reply_count_raw( $user_id);
$post_count   = (int) $topic_count + $reply_count;		
if ($post_count > 150) { 
//show here
}