At Facebook’s recent f8 conference, they announced some new features that get turned on by default. One of the most concerning is the “Instant personalization” feature. EFF has a good summary.
“Yesterday, Facebook announced Instant Personalization, whereby select websites would “personalize your experience using your public Facebook information.” The initial sites are Pandora, Yelp and Microsoft Docs. As Facebook CEO Mark Zuckerberg explained, this means that when you visit “Pandora for the first time, it can immediately start playing songs from bands you’ve liked.” Pandora, and other partners, can also link your real name and other Facebook information with everything you do on their site.”
Here is the link to the EFF Site and how to disable the “features”
The direct link to the howto video is below.