On one of the first days in Milan, one of my classmates made the observation that she has seen a lot of Italians wearing American flag related clothing. I at first doubted her, but once she started pointing them out, i have been unable to go anywhere without seeing an american flag shirt or baseball cap or bag or really anything that can fit an american flag on it.
I have several theories for why the American flag specifically (I have not seen anywhere near as much clothing with other flags) is so popular here. At our first Italian lesson, one of or assignments was to go up to random Italian people and ask them for their opinions on America. I was expecting opinions such as "obesity", "rednecks", or "racist". In retrospect I guess I was being pretty pessimistic about foreign opinions on America, but in reality we received answers that were more accurate. One of the questions was "What do you think of Americans?". The answer we got was "Tranquilla" or "Quiet". I was not expecting that answer at all. I think that answer alone totally shattered any preconceived notions I had on Italian's point of view of America. Now obviously one person does not speak for a whole country, but the person we had asked seemed to be a young, hip person who could probably at least depict a stereotype of Italian young-adults.
After having observed the different types of people that wear American flag related clothing and the stores that carry these clothes, it seemed that these people would be considered very similar to "hipsters" in America. I get the feeling that many of these people associate America with freedom and being able to express yourself. They see that American flag as a symbol of artistry and being a "free spirit".
There is no way I can really know why so many people where the American flag without asking them, and even they may not know, but I do think that it is a very interesting trend in Italian society.