One of the easiest ways to protect your privacy and security on a smartphone is set a passcode or biometric lock to enable disk encryption. That way if your phone gets lost or stolen, no one can take data off the device in a readable form. But not all smartphones\u2014and tablets, and smartwatches, and so on\u2014offer that protection. They don\u2019t have the processing power to deal with resource-intensive encryption.