Yesterday in Bermondsey Jenny Ellis, 27, an office worker from Central London, said she would hesitate before reprimanding someone for spitting at people from a bridge. "Someone could turn around and stab you. You could lose your life over something simple.
"If there was a man hitting a woman I would definitely intervene - but it would depend how tall the man was."
Kieran Pope, a 24 year-old scaffolder from East London, said a public- minded approach could stray into stupidity.
If a phone box was being vandalised? "It would depend on who was doing it," he said. "I wouldn't intervene if it could get me into trouble. The person could be a bit of a nutter. You don't know what people are like. If someone does that they are not all there."
He would almost certainly stop a man hitting his partner but would only stop a woman. "If she was stamping on his head with high heels then I would restrain her."
Sophie Kernon, a 23-year-old production company worker, from North London, said: "Racism makes me sick. I will verbally stand up against anyone being racist but when it comes to someone beating someone up I would hesitate because I am only a girl. But when the adrenalin starts to rush you don't know what you would do."
Would she stop a child spitting at passers-by? "I would probably laugh. Kids always do things like that."
In the Yorkshire commuter village of Horsforth, attitudes depended on the seriousness of the misdemeanour.
Sue Cheaton, 22, working in the village bakery, would not intervene if children were dropping litter or spitting. "It's not worth it. But if I saw someone kicking a dog I'd definitely react. People shouldn't cause pain for a laugh."
With phone box vandals, "it would depend on how many of them there were," she said. "A lot of kids these days get pretty violent. I've seen couples fighting and walked on by before. I felt guilty."
But a racist would be different. "Even if they look intimidating, I'd definitely intervene. Some things are not worth getting beaten up for, some are."
Anthony Scurrah, a former professional middleweight boxer, 6ft5ins, lean, muscular and tattooed, said: "I don't fear anybody, but kids are parents' responsibility and no parent should pretend he doesn't know what his kids are getting up to.
"For litter and spitting, I'd just think, `Idiots', but wouldn't bother saying more. If they were kicking a dog, it would depend. If the dog was yelping in pain, I'd ask them what they thought they were doing.
"If they were vandalising a phone box, I'd call the police on my mobile, and also say to them, `Come on lads'. I'd have to be wary about getting into a fight because of who I am, I'm reluctant to hurt people.
"A couple fighting and arguing, well, she might deserve to get hit, how do I know?
"In a racist attack I'd get in there straight away."
Jane Hollingsworth, 63, shopping in Morrison's store, said she would definitely `have a word' with people dropping litter, but not spitting.
"If they were hitting a dog I'd shout and call the police. Couples fighting I can't be dealing with, it's their business.
"If there were a racial attack, I would call the police."
Would you intervene if you saw:
Yobs spitting from a bridge on to passers-by?
Someone dropping litter?
A person hitting a dog?
Vandals damaging a phone box?
A couple having a fight?
White youths picking on a black youth?