The provider or operator of the remote system has ultimate control of his system. He has complete access to all areas of the system. He could easily examine the material. The prosecution would note the user could not reasonably protect his private data from provider or operator invasion. If there is no privacy, there can be no search and therefore no Fourth Amendment constitutional violation.
Law enforcement can retrieve the material.
The federal wiretap statutes, before the Electronic Communication Privacy Act of 1986, protected oral telephone communications from police interceptions. This protection was made in 1968 in response to electronic eavesdropping by government. The old law required that an interception of a wire communication be an aural acquisition of the communication. Therefore, a computer communication may come under the old law while being transmitted. The communication's conversion into computer stored data, thus no longer in transmission until retrieved, takes the communication out of the old statutory protection.