In a new ruling, the European Court of Justice ruledthat websites using Facebook' Like buttons need to warn their users about the collection and processing of their personal information. According to DW, websites using the button must obtain prior consent from users for the "collection and transmission of the data," meaning that they will now be held jointly responsiblefor letting users know that Facebook has access to their data. The Court found that it appears that a website cannot be considered to be a controller in respect of the operations involving data processing carried out by Facebook Ireland after those data have been transmitted to the latter. According to TechCrunch, this ruling is significant because Facebook's Like buttons transfer personal data automatically, which means that if websites are relying on visitors' 'consenting' to their data being shared with Facebook they will likely need to change how the plug-in functions to ensure no data is sent to Facebook prior to visitors being asked if they want their browsing to be tracked by the adtech giant.