vampirequeen This young woman had apparently been harassed constantly when passing the building site and had tried to ignore the whistles until one day one of the group of men stood in front of her and blocked her path. Can you not see that a young woman on her own might feel vulnerable in such a situation?
No-one has suggested that a man can't look at a woman - but there is such a thing as stepping over the line. For instance, a quick, appreciative glance at a person (male or female) from a person that finds them attractive is probably quite a natural response. A persistent stare is something entirely different. It's all about common sense and balance.
As JessM said, the statistics demonstrate that women don't imagine men can cause them harm - the fact is a considerable number of men do cause harm to a considerable number of women. When there is a spate of violent sexual assaults on women or non-domestic murders, other women are urged not to go out on their own, to ensure they get a taxi home, etc., etc., which is not house arrest but is certainly a restriction on their freedom to come and go as they please.