I mean, you've got the right to not answer the door. They just have the right to break the door down because of the lawful warrant. You don't have to help with your own incarceration, i.e. point out evidence they were unable to find, why would you be expected to do the same thing on their phone? Police can't force people to testify either. If your only evidence of a crime rests on the defendent's compliance you've got a poor case. If you can't tie an IP to a device on a specific date and time without forcing someone to open their own device and admit guilt and ownership, then you're really not trying hard enough. The only way that the police can prove who committed a crime on a cell phone that is encrypted is either admission of ownership or compulsion. Neither of which is evidence of a crime in and of itself. They would still have to prove that the person who owned the phone committed the crime, otherwise why have the burden of proof on the prosecutor? These aren't civil cases we're generally talking about where the evidence requirement is lighter these are criminal cases where, as far as I understand anyways, the burdens are much higher. Add to that a cell phone is essentially a tracking device. While your position is certainly a reasonable one to take, I don't think it truly encapsulates the intent of our court system as designed and in fact expressly works against innocent until proven guilty.