I had to ride home later in the evening on TRAX by myself the other night.  I wasn't scared or nervous... let's just say, I was "cautious".
I had my car keys threaded between my knuckles so I looked like Wolverine from the X-men movie.  If someone tried to accost me I would scrap the keys down their face then police could search for the deeply scratched man and I would recognize him as my attacker.
I kept one eye out for everyone around me even though I was pretending to read my Nook.
There were several boys, late teens or early 20's in several of the seats in front of me.  They were loud and laughing, their pants sagged, and they had ball caps screwed down tight on the top of their heads.  Worst of all, they all were wearing dark hoodies!
And yes, some had darker skin color than me...

One came around "just asking a brother for some change for some food".  I didn't know what I was going to say when he got to me.  Say "no" and then get mugged?  "Yes" and then have them all see me fumbling with money so I would just end up robbed?  Thank goodness he didn't ask me.
  Then at the next couple of stops, most of the young men got off.  I didn't look up, I just kept pretending to be reading because I noticed one larger black young man alone, sitting two seats in front of me.  He was playing his music loudly so ALL could enjoy (?) it.

 When suddenly I heard a voice say, "Ma'am?"

I let it go, I ignored it.  I am deeply reading, can't he see?  I feel my keys in my hand. I feel my heart rate  increase a bit.
"Ma'am?"  He says a bit louder this time.

I had to.. I had to look up to see if it was me he was calling to.
And he was looking right at me.  He had turned around in his seat and was looking right at me.  Dark ball cap, dark hoody jacket, loud music.
"Yes", I answered in my most sweet old lady please-don't-hurt-me-I-could-be-your-mother voice.

"Is the language in this music to harsh for you?  Sometimes they sing with some pretty bad language and I wouldn't want to offend you."

 I stared at him for an eternity before all my senses came back to me and I answered, "I teach junior high school.  That language, which I can't even hear, is probably not anything like what I hear in the halls at school".
"You're kidding", he answers.  "They get away with bad language in schools here?"
 "Well they shouldn't but when they think no one old is listening it really flows out",  I answered.

"Well I apologize if this offends but I really like the music and you have a nice day now, ma'am", he says back to me so sweetly that I carefully put the keys back into my pocket and started to really read my book.