Here's an easy thing you can do right now to improve your digital security hygiene. Pull out your iPhone, open Settings, go into the Siri settings, and turn off Access When Locked. Do it on your iPad while you're at it. Go ahead and do it for your family and friends, too, at holiday functions when you need to deflect personal questions. In the battle of the smart assistants, every tech giant hopes to hook you on its voice-activated helper.