New terms and conditions going into effect on November 11, 2013 for Google Plus members will permit Google to use your photo in ads.
Here’s how to turn it off:
The following is long but I’m assuming you haven’t used Google Plus since you signed up!
1. Log into your Google / Gmail / Google Plus account (it’s all the same)
2. go to plus.google.com (this is your Google+ homepage)
3. On the left, find the “Home” tab. Put your mouse on it. Scroll down to “Settings.”
4. The third bold section is “Shared Endorsements” — hit edit.
5. Scroll down and un-check the box, “Based on my activity, Google may show my name and profile photo….”
6. Hit “save.”
7. On the same page, scroll back up and hit “Back to Account Settings” in top left.
8. Check to make sure Shared Endorsements is “off” (if it isn’t, you likely did not save in steps 4-6).
9. You’re done.