I could say that, even for someone you've known long time, even for someone who used to be your good friend, even for someone around you but you don't know they're exist, and for someone you don't really know at all.
When i was in junior high, i remember, at the mo, so popular this thing. bangles. with some words on it. yes, "World Without Stranger" with so many various color.
People all over the world claimed. There would be no more "stranger" from that time. But hey ? it's only "latest trend" at the mo. You used that bangles, but you didn't do what that word mean ! Did you really mean it or it just a common word for you guys ?
from the very simple things. People around you. How could it be ? you are in one room for a long duration, but you don't know each other... even for a name.
Try to respect, and let's start "world without stranger" from this time :)