Defendant told someone in a recorded jail call that he knew was being recorded his Facebook ID and password so it could be changed. That was a waiver of his reasonable expectation of privacy in the information on his Facebook account that AFOSI could access. Defendant was awaiting court martial in a county jail. United States v. Langhorne, 2017 CCA LEXIS 746 (A.F. Ct. Crim. App. Dec. 5, 2017):
… When Appellant voluntarily revealed his Facebook username and password to TSgt PF, he no longer had a reasonable expectation of privacy in his Facebook account. The fact that Appellant was aware that his telephone conversation was being recorded and subject to monitoring further cements the conclusion that when AFOSI used the recorded information to access and copy his Facebook messages, the investigator’s actions did not constitute a “search” under the Fourth Amendment, since they did not violate a reasonable expectation of privacy. Accordingly, the military judge did not abuse his discretion when he overruled the Defense objection and admitted Appellant’s Facebook messages.