in reply to delete single user

Let's do this on paper:

  1. Write down a list of everybody in the room.
  2. Send one person out of the room.
  3. Announce all the names on the list.

Notice I didn't include a step to draw a line through the name on the list of the person we sent out of the room? You are deleting a user, but then printing out the list that you generated before the delete.

The order should be:

  1. Delete a user.
  2. Fetch a list.
  3. Print the list.

That's still a terrible plan; as the user list grows so will your memory requirements, network traffic, and the requirements for memory in peoples' browsers.