Two smiley faces: Episode two

The emoji, invented in Japan in the 1990s, and now standardised on every device and platform we have, has become a new type of global communication. Whether you love them or hate them, they stir up surprisingly strong feelings and the fight for representation on the emoji keyboard can get very heated. In episode two, we explore how sometimes, emoji are more than they seem. In fact, for some dating app users, criminal gangs and even human traffickers, emoji take on secret meanings. The BBC's Vivienne Nunis and Sarah Treanor are here to crack the code. (Episode 2 of 6.)