How to disable automatic picture upload to Google+
Open the Google Plus app, go to settings and disable "instant-upload".



Please note if you enabled it:
Each photo you take will be uploaded to Google Plus' staging area but not be shared immediately. It's just for convenience so that you don't have to grab your phone if you want to share some past pictures you took with your mobile. You will be able to to share from any browser you're logged in at any later time you want.

You can also select if you only want to instant-upload when you're on wifi.