Android 4.3 feature Privacy Guard
If we see random apps on play store like whatsup app, or any other app. most of the time we install the application without noticing authorization access we are giving to them.
So what is Privacy Guard is all about.
If you are running Android 4.3, you just need to go Setting --> Security --> Privacy Guard.
Now you can install any random application and go to privacy gaurd setting and find out if that application need to read your private data (Contacts and messages).
When I looked into Privacy guard of my apps even popular apps like Dolphins browser, Smart Tools, eRail.in, Photoshop Express, GPS Test (tiny but useful app) these apps are looking for private data.
I don't think these apps ever need to access phone book or messages.