The last time I was in Termini station, a man rushed up to "help" me as soon as I arrived. I speak fluent Italian and had used the machines many times before. I told the man I didn't need any help, but he kept hovering around me while I was pulling out my credit card. I asked him to please leave my vicinity, and he backed up only a little. I told him that if he didn't back off, I was going to report him to the police. He laughed and said, "Go ahead!". In fact, there were no police to be found in the station at that moment, which I thought was odd.
Later I found some policemen in their little office (where they hadn't been half an hour earlier) and told them that there were some very persistent (and aggressive) helpers at the ticket machines. They said, "We'll take care of that!", but the way they looked at each other and their tone of voice led me to believe that they had no intention of doing anything.
I stood around and observed the scene at the ticket machines for a while, and the helpers were definitely an organized squad, with a boss.