Next time pay even more attention when clicking the Facebook Like button, because now social apps such as Foursquare and Instagram — and eventually all — have the ability to self-publish your friends Facebook notifications.
This comes from new changes to Open Graph, where the social network introduced to developers a new “Like” button, that app builders must implement moving forward, and also includes a mechanism to publish your next like to Facebook.
For example, if one of your friends post a new photo to Instagram in the social network, and you add a new like from the app to it, that ‘like’ will also appear on Facebook as a notification that says, e.g., “Joshua likes your photo on Instagram.”
Now, unlike the traditional Facebook “Like” button you use everyday, you have to authorize the app to post the notification to the social network by changing the app configuration from the Account Settings section. This is a nice opt-out to have, but it is just sad that because the privacy settings are designed to confuse instead of help, many users will not even realize they can opt-out. Now you know, so just be careful — if this is a concern to you, of course.
Source Facebook via Gizmodo
