"Harassment on the train "

I was sitting on the train and we got to the Monroe stop and a young lady got on and proceeded to sit on the other side of the car and a guy was following her. She then got up to move, to get away from him, and sat across from me. He sat right next to her talking to her. I had my headphones on and couldn't hear anything, but turned my music off because I could tell she was shaking and looked scared. He kept shoving his phone to her face saying " give me your number" she looked so scared and tried to ignore him. There were a lot of people on the train, but no one was doing anything, and I knew I needed to do something to get her out of this situation. I looked in her direction and pretended like I knew her and said "Emily is that you?" She looked right at me andnknewbex6what I was trying to do, and she jumped up and sat next to me saying hi. We hugged each other and as we were hugging, I whispered in her ear to get off of at the stop I was getting off at. So we can be together. She still has a while to go on the train, but she agreed to do so. He was still being aggressive and asking for her number, but she grabbed his phone and threw it across the train. He was pretty pissed and seemed like he wanted to punch her, but I grabbed my phone and looked at him and showing him I was about to call 911. He walked away and proceeded to go on the next car. We got to the stop and I told her to get off with me. I looked around to make sure he wasn't following her, and luckily, he didn't. We walked up the train station and I told her to report him to the agent at the station, to let them know what happened. I also told her to wait for the next train to go wherever she needs to be. We exchanged names, hugged and she thanked me for helping her. This is unfortunately not the first time I have been in a situation like this. I have witnessed something like this before and always jumped to help because I would hope someone would do the same for me if I were in their shoes.