I just went to Facebook and did the following:
Accounts > Privacy Settings > Applications and Web Sites > Instant Personalization Pilot Program
At the bottom was a box to uncheck to disable this (otherwise automatically enabled for you) “feature.”
Then you may want to check:
ccounts > Privacy Settings > Applications and Web Sites > What You Share
From there click on Learn More. Nearly hidden down at the very bottom is the link This page.
Go to that page and under each applicationi will be Edit Settings. If you haven't changed them, they are probably set to share with Everyone.
The most restrictive setting in the list is Only Friends which is probably okay. If you want them to be more restricted, then you have to choose Customize where you can finally set them to Only Me if you wish.