One of the difficulties Italy has in collecting taxes is that a lot of the economy is still on a cash basis. When you for instance pay for several nights lodging with a big roll of Euros you do wonder if this income ever gets reported. Oh, credit cards are accepted some places. Restaurants for instance will usually take them.
On our last day in Rome I snapped a quick picture of this place on the Via Trastevere. I wonder if the credit card machine ( called a Point of Service) was really broken or not. And I do like the inadvertant pun!