I ride the CTA train everyday in Chicago.
Luckily I have not seen anything this bad but once an agressive bum walked on the train and went one on one to the passengers if they had money. One preppy lady who had her suitcase with her (obviously from the O'hair airport) told him "no" but he just kept saying "oh come on... you have some money"...
Nobody said anything to him (including myself) I simply did not want to get hurt ofcorse, but i got up and went to the front of the train. (i moved from car to car) the guy tried to stop me yelling "Where are you going, I'm just asking for money" But anyway, when the train stopped at the next station I got out and told the driver that this bum (who was smoking by the way) was bothering the passengers. The driver just said "OK" and that was it. He did nothing about it.
I was amazed though that I was the only person who got up. Eveyone else just sat there hoping he would just leave them alone.
The funny thing was in the front of the train where I went to were these "hoodlums" who were laughing and having a good time. When the bum came to the front of the train and asked them for money they yelled "Ain't nobody got money on this train man, get cho stankin' poor-ass off!" He finally got off the train. Ha ha