Fan on Web
There are two places that you can remove items from your list. You can do it while in a specific movie or TV show by clicking the 'highlighted' list icon. (Icons that are not highlighted are not in your lists. Icons that are highlighted will be in your lists.) Or, you can remove while in the list by clicking the item to see the drop down (iOS) or clicking to 'unhighlight' from the item itself.
Glengarry Glen Ross is in my SeenIt and I'm a Fan according to the highlighted icons above.
Trance is not in any of my lists, as you will notice that none of the list icons are 'highlighted'.
You can also remove items while in the list itself using the same method of clicking to 'highlight' or 'unhighlight'.