Think if someone had used your smartphone for a while and get your identity details what he/she can do it with your handset. They can able to text people make calls, they can post your sensitive pictures to facebook or social site, they can also get access your bank accounts and make purchase with your bank account on your name. They can do anything which is possible by your smartphones. i was searching for the solution and i found this on web. http://techontrend.com/hide-apps-on-android/