Meta goes on trial in a landmark case about children’s addiction to social media, voters cast ballots in critical primary elections in four states and millions of Americans are under heat alerts across the South. For more context and news coverage of the most important stories of our day, click here: https://www.nbcnews.com » Subscribe to NBC News: http://nbcnews.to/SubscribeToNBC » Subscribe to Here's the Scoop podcast: https://www.nbcnews.com/heres-the-scoop-daily-podcast » NBC News App: https://apps.nbcnews.com/mobile » Breaking News Alerts: https://link.nbcnews.com/join/5cj/breaking-news-signup?cid=sm_npd_nn_yt_bn-clip_190621 » Visit NBCNews.Com: http://nbcnews.to/ReadNBC » Find NBC News on Facebook: http://nbcnews.to/LikeNBC » Follow NBC News on Twitter: http://nbcnews.to/FollowNBC » Follow NBC News on Instagram: http://nbcnews.to/InstaNBC #news #meta #ai