That would be worse than confusing. I forced this on Brian, and I now repent and will remove this. They must be removed when the client sends a QUIT command. The server may keep them around if the client session is terminated without a QUIT command, but it should have some way to periodicly clean up old search results virtual newsgroups. There is no way to get the article in multiple pieces, and no NNTP way to stop the transfer.
Termination is all there is.
Given that, I want to support it without having the search results drop out from under the client everytime they do this. I think that with the new language, something like this would then be up to the server, which is as it should be. It does not persist beyond the end of the session. I want to let someone reconnect to a search done in a previous session. If the server supports robust access control, and the user is authenticated at the time the search is done, it can protect the search results using whatever means it uses to control access to newsgroups.