I too have spent some time in Italia, and have always been treated well by the locals. I had a few problems, especially in the area of Napoli, but by and large, the Italians were full of smiles and good cheer.
During my tour, there was a lot of anti-US military stuff going on in Rome. Red Brigades group, if I remember correctly. They enjoyed pulling cobblestones from the streets and throwing them, then after a short clash with the local police, disappearing.
A decade later I was stationed in England, and taking classes through the U of Md. One of my instructors had a very interesting background. He was studying for a Doctorate at one of the Oxford University colleges, and teaching at U of Md to pay the bills. He was a former US Army CPT, a specialist in intel/counter intel, and had been stationed in Rome at the time I was there. He had been undercover pretending to be an ex-pat war protester and was an insider/instigator in the Rome rioting. He claimed to have tossed more than a few cobblestones! All the while, he was reporting intel back to the army.