Cutting ones finger nails on the train - YUCK

Okay so i think i said this on facebook as well. Why is it okay to cut your finger nails on the train but not talk on your mobile phone. I just dont understand. So here is the story. I was standing on the train and this lady was standing next to me. She turned towards the wall as the Japanese tend to do. I guess cause staring at the wall is more fun than people watching. Anyway, then she got out her nail clippers and started cutting her finger nails. This was not the first time i had seen this. A teenage boy had sat next to me and done it and i watched a mum cut her little girl's finger nails. But both of those times, they took the nails with them. This GROSS lady just left them on the floor. I wanted to vomit and it still makes my skin crawl. I took some photos and i think she was onto me because she turned away at one point. But i got them and here they are.