Facebook has blocked Twitter’s new Vine app from being able to find your Facebook friends on the service. The app launched this morning, and previously offered users a way to see which of their Twitter and Facebook friends were also using the service, in addition to contacts stored in their phone. A request to search for Facebook friends on Vine now yields a pop-up message indicating that the app is not authorized to make the Facebook request. The dialog box was first spotted by a Verge reader. A Twitter spokesperson told Mashable the company didn’t have anything to share beyond that notification. We’ve reached out to Facebook for comment. We’re also currently unable to share videos from Vine on Facebook. While we did not receive an error message to this effect, videos shared from the app have still not appeared on our timeline.