Facebook announced it will their users' complete browsing history to improve targeting through ads. User history will be analyzed in order to increase the relevance of Facebook ads.
What will this update do?
This change will allow Facebook to increase its ability to target members through "like" "share" and "send" buttons on partner sites and apps. In addition, it will use plugins that allow for sharing comments. This update will take place in US and internationally over the next upcoming months.
What about my privacy rights?
If you don't want to be part of the targeted ads network, it's possible to manage you privacy through a management console on Facebook. You'll be able to modify informations and deactivate ads based on your browsing habits.
However, instead of managing the rights you give to Facebook, you can opt to search for products on your own?
For more information, here's a video to watch.