How your phone and fitness band could end up giving evidence against you

In criminal proceedings from accident claims to terrorism charges, how should the authorities strike the appropriate balance between justice and privacy?

A criminal suspect can't be forced to divulge their phone passcode, a US circuit court judge ruled in October 2014. Yet law enforcement officials can compel a suspect to provide a fingerprint - which they can then use to unlock the phone and obtain data which may prove the case against them.

In an ongoing Canadian civil case, activity data from a Fitbit fitness band is being used to determine the truthfulness of an accident victim's claim that she is less active now than before the accident.