Of the examples that you list above, I agree that communication (what would have previously happened with letters) has mainly moved to the net. To the extent th

Of the examples that you list above, I agree that communication (what would have previously happened with letters) has mainly moved to the net. To the extent that receipts have moved, the government has access (either directly or through a subpoena) to many forms of electronic records. My original point was that in criminal cases, there is a treasure trove of physical evidence available to the government, and the value of this evidence has been under-weighted in discussions about encryption. - If the suspect has dangerous equipment or substances at that location, then the government can gain access to and analyze those physical materials. - If the suspect received deliveries to his address, then the government can get records from FexEx, UPS, USPS. - If the suspect used a phone, the government can get access to carrier calls (I agree that this may not be possible for app-based calls). - If the government finds credit cards used by the suspect (either by finding the physical card or by using the purchase history of any cars, residences, or other tools used by the suspect), then they can search the history of those cards.