Android Ransomware Threatens To Share Your Browsing History With Your Friends (symantec.com)
An anonymous reader writes: The newly discovered Lockdroid ransomware is unique in two ways. First it uses perfectly overlaid popups to trick users into giving it admin privileges. This trick works on devices running Android versions prior to 5.0 (Lollipop), which means 67% of all Android smartphones. Secondly, after it encrypts files and asks for a ransom, it also steals the user's browsing history and contacts list, and blackmails the user to pay the ransom, or his browsing history will be forwarded to his contacts.
If you stick with Google Play, you're safe from this.
It is only a problem if you side load apps from untrusted sources.