"Since 2013, millions of people have turned to Vine to laugh at loops and see creativity unfold. Today, we are sharing the news that in the coming months we’ll be discontinuing the mobile app," Vine wrote in a blog post. But why have they decided to pull the plug? A report by Yfoundations, a policy group that looks at issues affecting young people, suggests that attempts to scare teenagers about the risks of expressing sexuality online are likely to be ineffective.