Mobile devices have upgraded from normal java-based phones whose basic functionality was calling, messaging, and storing contact information to a more adaptive operating system like Symbian, iOS, and Android, which have smart features like e-mail, audio player, camera, etc. Gradually, everyone started relying more and more on these mobile devices. This led to an increase in the number of cell phone hackers. Common ways that a hacker gets access to your phone is via phishing, shoulder surfing, piggybacking, etc. There are countermeasures to this like bookmarking your most visited sites, using VPN, using encryption algorithms. Data theft and identity theft are a new concern for today's user; this chapter is to educate the end user of different ways in which their privacy can be invaded via a mobile phone. This chapter will help the researchers to know the mindset of a cell phone hacker and what are the potential damages that can be caused by them and strategies to prevent them.