These issues have actually been litigated in court.  The broad consensus is that yes, the police can use a surveillance plane can take pictures of you without first obtaining a warrant (Florida v. Riley), but no, they can&#x27;t use infrared camera to look inside your home without a warrant. (Kyllo v. United States)<p>None of these cases are really analogous to the Tor case.  Generally speaking, you have no reasonable expectation of privacy that information that you voluntarily provide to a third party will be kept confidential.  This is why the police doesn&#x27;t need a warrant to get your phone records or to obtain your IP address.<p>You bring up mail, which is an interesting case.  Conents of a sealed mail IS protected by the Fourth Amendment - it&#x27;s just that the government usually relies on the &quot;exigent circumstances&quot; exception to the warrant requirement (basically, showing that there is probable cause to search the mail but that there is no time to obtain a warrant).  The government can&#x27;t just mass-open all sealed mails and look at their contents.