Face it: the world has been changed by the omnipresent pocket bulge known as a smartphone. Once upon a time, people indexed phone numbers of their friends into nature's smartphone, i.e., your brain, but seriously, can you actually recite a phone number belonging to any of your five closest friends? Beyond keeping track of your personal contacts, so many more of life's habits and activities have been streamlined through those handheld devices: financial information, sensitive account info for a myriad of websites, a virtual rolodex of professional contacts, personal (and sometimes extremely personal) photos, medical information, where you live, documents for work, etc. Veritably, smartphones have accidentally become the basket in which we've stuffed nearly all of our eggs.
Given this wholesale dependency on smartphones, you can only imagine the severity of losing one (and if you're one of the many, many people in this world that don't have to imagine what it's like to lose a phone, you have my sympathies). Nobody's immune from this, either: just ask that misfortunate Apple employee whose affinity for weissbier ended up with him losing a prototype to the iPhone 4 long before the phone was supposed to be released.
In fact, you should probably go ahead and assume that you will eventually lose your smartphone and, along with it, most of the details of your life. Concerning that second part, studies show that cases of identity fraud of grown 14% since smartphones became an ubiquitous utility in society. Yes, you can sometimes use iCloud or some similar type of service to track down your phone but don't bank on that; and even if you do track it down, your information will still have been in the hands of some brigand for some amount of time. Just assume you're going to lose the phone and start protecting yourself now. BackgroundCheck.org put together an infographic to scare you into taking the proper steps to secure your smartphone and thereby your identity. So look, listen, and buckle up that phone.