What would you do?

You are minding your own business when you see an elderly lady being hassled by a young man. What would you do? Call the Police? That's OK, but now the young man is hitting the women. Now what? Call the Police a second time? Jump up and down waving your arms? (as recommended by the Home Office) Fine, that might work. But what if the elderly lady is your mother? Would that change things?

Are you still jumping up and down?