The encrypted messaging app Telegram is haunted by a single question - if it really is as secure as it claims to be, why does Vladimir Putin allow it to be used in Russia?And should Russian dissidents, independent journalists and Ukrainian soldiers use this Wild West of an app, where you can find everything from porn to drugs to faked propaganda videos? Answering those questions takes Helen on a journey that begins with a young Russian entrepreneur throwing 5,000 rouble notes off a balcony, folded like paper aeroplanes, and finishes with him in exile in Dubai, rich beyond his wildest dreams. But what does Pavel Durov, the founder of Telegram, really believe? Producer: Tom Pooley
Assistant Producer: Orla O'Brien
Sound Design: Louis Blatherwick 
Editor: Craig Templeton Smith 
Original Music: Coach ConradA Tempo &amp; Talker production for BBC Radio 4

Helen Lewis Has Left the Chat. Have you ever been trapped in a group chat nightmare, either grabbing the popcorn or wondering how to leave without causing a scene? Who's the admin in your family group, and do they wield that power responsibly? Do you ever wonder if it's appropriate to use emojis when talking to your boss? The rise of instant messaging has made our social and professional lives faster, more casual — and more chaotic. But amid all the discussion of the effects of public social media, such as Facebook and Twitter, there has been relatively little attention paid to private social networks—the direct message and the group chat — and how they are shaping our relationships and our world. In this series, Helen Lewis looks at the secret world of instant messaging, meeting a woman who married a chatbot, discovering how Russian dissidents are fighting a propaganda war, and hearing the inside story of how Britain ended up governed from a single WhatsApp group. It's a strange new world where workplace rebellions are conducted through duelling emojis and military secrets are traded on chat forums about a children's cartoon. It's also a world where you can never be quite sure who you're talking to—and who's eavesdropping on you.