A campaign has been launched to encourage Londoners to “become a friend” to fellow passengers being harassed on the capital’s public transport network.A hard-hitting film showing real-life examples of people being targeted on the bus, Tube and train platform is being shown from Monday in cinemas and on TV.Transport for London wants to encourage passengers to become “active bystanders” and use distraction techniques to help victims, or to offer support and information about what they have witnessed in the immediate aftermath of an incident.