Google Android 4.4 KitKat brings some changes which will definitely raise some eyebrows, specially with users who are touchy about their privacy. After amending their TOS which enables Google to use your photos in advertisements all across the web via Google Shared Endorsement, the company is now making your Google+ photo connected to your phone number which will be shown to any user on their Android mobile phone as Caller ID when they dial your phone number. Currently this "Smart Caller ID" feature which is now live on Android 4.4 shows caller ID photos pulled automatically from verified Google Places and Google Apps customer accounts. This feature will however get expended to include personal Google+ accounts in early 2014, after this expansion anyone with an verified phone number and discovery turned on in G+ profile will have their names and profile photos display on each others screen even if they have not exchanged/saved contact information. Thankfully, users can easily opt-out and disable this feature as shown below.
Opting out from this automated phone number discovery for your phone number(s) is easy, simply visit https://www.google.com/settings/phone and uncheck the "Help people who have your phone number find you on Google services and connect with you." option as shown below.