Hi there, I've just recieved a letter through the post from Mersey rail myself this morning. I too had my feet on the metal frame next to the seats, not on the actual fabric. I was approached by two guys in high viz jackets, and there was no one else in the carriage, they asked for my ticket and said they would accompany me off at my stop. Before we even left the train, one of the guys started to fill out his notepad, and once on the platform already wrote down that I had said yes to being interviewed. They also read me my rights, which actually made me believe that they were police officers for a moment. They said that the company does not tell them what is put into the letters. I'm unsure how to proceed, as my feet were not actually on the seat and I did apologise, however I am currently a student myself and do not wish to get a criminal record for such a stupid error.