This is meant to test if it is possible to listen in on a websocket, if you know or guess the threadId. Normally, you can use websockets to broadcast to different users that are subscribed to the same websocket channel but we always close the channel immediately after sending a response as we have no broadcasting use cases yet. However, this does mean that without an identifying mechanism, someone could still listen in he manages to establish his connection exactly at the same time. We don't want this of course.