Replace email with private communication.
From http://itlaw.wikia.com/wiki/Reasonable_expectation_of_privacy
"With respect to the content of an Internet communication (such as an e-mail), a computer user generally has a legitimate expectation of privacy in that content while it is in transmission over the Internet. To date, the federal courts appear to agree that the sender of an e-mail, like the sender of a letter via first-class mail, has an objectively reasonable expectation of privacy in the content of a message while it is in transmission.[17] In United States v. Maxwell,[18] the court addressed e-mail privacy:
“ E-mail transmissions are not unlike other forms of modern communication. We can draw parallels from these other mediums. For example, if a sender of first-class mail seals an envelope and addresses it to another person, the sender can reasonably expect the contents to remain private and free from the eyes of the police absent a search warrant founded upon probable cause. However, once the letter is received and opened, the destiny of the letter then lies in the control of the recipient of the letter, not the sender, absent some legal privilege.[19] ”
“ Drawing from these parallels, we can say that the transmitter of an e-mail message enjoys a reasonable expectation that police officials will not intercept the transmission without probable cause and a search warrant. However, once the transmissions are received by another person, the transmitter no longer controls its destiny. In a sense, e-mail is like a letter. It is sent and lies sealed in the computer until the recipient opens his or her computer and retrieves the transmission. The sender enjoys a reasonable expectation that the initial transmission will not be intercepted by the police. The fact that an unauthorized "hacker" might intercept an e-mail message does not diminish the legitimate expectation of privacy in any way.[20] ”
“ Expectations of privacy in e-mail transmissions depend in large part on the type of e-mail involved and the intended recipient. Messages sent to the public at large in the "chat room" or e-mail that is "forwarded" from correspondent to correspondent lose any semblance of privacy. Once these transmissions are sent out to more and more subscribers, the subsequent expectation of privacy incrementally diminishes. This loss of an expectation of privacy, however, only goes to these specific pieces of mail for which privacy interests were lessened and ultimately abandoned.[21]
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