Not a legal eagle, but I would take issue with Turley's (or anyone's) position that "private" stuff stored on a government server, temporarily or not, is truly "private." It is no longer private in the sense that it can't be evidentiary, in my non-legal opinion.
This is completely apart from the constitutional provision that search warrants must describe in particular the things to be searched for. It is not like developing a search warrant for an external entity --it is the government's own property in the first place.
I am sure that legal eagles could make a "debating team"-type case that it is private, using obscure case law and "rules of evidence" precedents, but that would be another situation where The Law demonstrates itself to be an ass.
Which, itself, is not uncommon.
Terry, 230RN