Can you really help someone you don't know on the street?
If I talk about street, then there might be a lot of people. Now the question is will you help, and the answer is yes if I can then I will surely help whether he is a known person or a unknown person.
I will give an example, there was an accident happened on the road and I was on a bike, though everyone was helping those guys who need help, but there was no cop to be seen. That time I went and informed the cop to come to the scene and talk to the higher authority to get some help. This way I am not directly helping the people who needs help, but indirectly done my job to be a better person.