Naomi > No one knows who that bloke sitting next to them on the train is.
Yes, a stranger is a stranger.
We all encounter lots of strangers in our everyday lives and could come to grief in various ways from simply looking at someone the wrong way, or just being in the wrong place when a seriously mentally disturbed person picks you out.
What I continue to hear and read though is 'how so you spot a good Muslim from a bad one'?
The answer is you can't, just like any stranger.