This deals only with the comment feature. Although I love YouTube, it has a serious drawback when it comes to the ability to leave comments for videos.
When you leave a comment on a video, others may or may not see it. Comment posters on YouTube not given a courtesy notification that their post is hidden from anyone else's view, when such is the case. It is extremely frustrating when viewing posts days later, to find that no one else can see the post you made. You are provided no clue as to why your post was effectively banned, it just is. It seems this system is seriously broken.