We just finished a trip that included Istanbul and southern Italy. On our first pass through Rome Centrale I noticed a person that stood out, I can't remember names but I have faces down. On our way out of Rome several days later, I saw the same person and thought what a coincidence that I would see him again. We were standing near a ticket machine and there was a family trying to buy tickets when the man got in line behind them and began it get very close in to them. He had a pack on the front of him and his hands were in front as he crowded in, the family was focusing on the machine. At this point we intervened and asked the family if the person behind them was with them, he was not. Even after being called out, he kept crowding in, looking over their shoulders. At least one of them finally turned to face him and back him off a bit. If someone gets close, be very aware and don't hesitate to force them back.
There are more of those types at Termini. I had once a man who was very eager to help me with one of those ticket machines. I'm not sure whether I was very polite when thanking him for his offer.
On our RS Best of Italy tour, our tour guide Ferdi, was very good in watching out for the tour members when we got in a crowd. When we were in the Uffzi on Florence, we had a very good local guide. We often found many tourists crowding in to hear what he had to say. Ferdi was always behind us watching our backs. One time he even stopped the local guide from speaking and announce to everyone who was not a tour member that he didn't mind them listening, but they had to step back two feet from the tour members. He said he didn't know what their intentions were, but he just wanted to keep us safe from having any pockets picked. Evidently, he saw something in the crowd that he didn't like.
I've encountered similar types in Rome, Milan and other places in Italy (mostly in the larger cities), and I also found them to be a darn nuisance. On one occasion when trying to buy Metro tickets in Milan, a swarm of young Roma girls kept badgering me to "help buy ticket", and even after telling them to "get lost" they kept swooping in like vultures from different directions. I finally gave up and walked to the nearest ticket office and bought a day pass, and didn't have to be annoyed by them for the rest of the day.
There was a good resolution to that situation though. As I was leaving the ticket office, a group of about 8 police officers swooped in on the scammers and they (along with their male "handlers") were unceremoniously ejected from the station.