Instant Personalization was a pilot program that shared Facebook account information with affiliated sites, such as sharing a user's list of "liked" bands with a music website, so that when the user visits the site, their preferred music plays automatically. The EFF noted that "For users that have not opted out, Instant Personalization is instant data leakage. As soon as you visit the sites in the pilot program (Yelp, Pandora, and Microsoft Docs) the sites can access your name, your picture, your gender, your current location, your list of friends, all the Pages you have Liked—everything Facebook classifies as public information. Even if you opt-out of Instant Personalization, there's still data leakage if your friends use Instant Personalization websites—their activities can give away information about you, unless you block those applications individually."
