I was on a tube train in London at the weekend and there was a chap who obviously was suffering from severe mental health /addiction issues and was abusing other passengers. He particularly targeted a couple opposite him who were middle aged, he was shouting at them about God and then called the woman vile and ugly and kept shouting at her and asking her why she was wearing a mask. Everyone just pretended everything was fine and ignored him. He then got up and moved over to a young woman who was sitting in the seat next to the door, he was shouting in her face, she got up and started moving away and he went to follow her. She was obviously frightened. A middle aged woman then blocked him from the young woman and asked him why he was shouting at her and could he see she was scared. He then started shouting at the woman who intervened and was telling her to mind her own business , after a bit of shouting she told him to get off the train - to my surprise and I suspect the other passengers he got off the train. I was full of admiration for the woman who had intervened when everyone else was ignoring the situation, she put herself in a potentially dangerous situation on behalf of a stranger. I was at the other end of the carriage but could have moved over to help the young woman.... I really like to think that if no-one else had intervened, that I would have done something but I'm truthfully not sure that I would have been brave enough. I am aware of the term 'the bystander effect' and this was an example of this. Somebody expects someone else to resolve a situation (I'm including myself in this). Would you have intervened?