1. A method comprising: at an electronic device: while the device is in a locked state, receiving non-voice authentication information from a user to put the device into an unlocked state; receiving a first speech input from the user; in response to authenticating that the user is an authorized user of the device, transmitting the first speech input to a voiceprint service for generating a voiceprint based on the first speech input; receiving a second speech input at the device while the device is in a locked state, the second speech input including a command associated with a restricted feature of the device; determining whether the second speech input was spoken by an authorized user of the device, the determining including comparing the second speech input to the generated voiceprint; while comparing the second speech input to the voiceprint, processing the second speech input to identify the command; and upon determining that the second speech input was spoken by the authorized user, providing access to the restricted feature of the device according to the command included in the second speech input, where the method is performed by one or more processors of the device.