So says Investor's Business Daily, here:
In 2012, the Obama campaign encouraged supporters to download an Obama 2012 Facebook app that, when activated, let the campaign collect Facebook data both on users and their friends.
According to a July 2012 MIT Technology Review article, when you installed the app, "it said it would grab information about my friends: their birth dates, locations, and 'likes.' "
The campaign boasted that more than a million people downloaded the app, which, given an average friend-list size of 190, means that as many as 190 million had at least some of their Facebook data vacuumed up by the Obama campaign — without their knowledge or consent.
If anything, Facebook made it easy for Obama to do so. A former campaign director, Carol Davidsen, tweeted that "Facebook was surprised we were able to suck out the whole social graph, but they didn't stop us once they realized that was what we were doing."
More at the link.