Facebook's new photo-sharing app, Moments, http://www.digitaltrends.com/mobile/facebook-moments-share-photos-news/ lets users share photos privately based on named events and uses facial recognition technology — which is why it won't be rolling out in Europe quite yet.

The head of European policy for Facebook said regulators are requiring Facebook to offer an opt-in for Europeans, whereas it was automatically rolled out to all Facebook users in the United States this week.