Do you speak with them or do you get the conductor? Lets be fair, they should be punched in the face.
Depends. I've done it myself. Once a lady had her feet up on the seat and her bags on the seats next to her taking up an entire 4-seater. The look she gave me when I told her to put her shoes on and put her bags up was priceless. She started grumbling under her breath, you know, because she was mad at me and I said loudly, "are you talking to me? I can't hear you." Grumbled, asked her again, she shut her mouth the entire ride home after that. That was years ago.
The conductors are pretty proactive about that.