What are the laws in Italy about photographs of this nature taken without the subjects' consent?
In general terms if you are in a public place, for example on the street, you may be photographed, If you are in a private place you have the right to privacy. An exception would be if you are committing a crime, in that case you may be photographed or filmed. Just as in other countries the right of public interest may also be a consideration.
I would suggest that in this case the photographs were taken in a public place and regard a person of public interest. The one provision may be in the case that a photo is published with the intent to do real harm to a person. That becomes very difficult to judge where the line is crossed.
In an interesting aside anyone posing for a photo in effect gives permission to all present to take a photo however if that photo is then used to make money, without permission, the subject(s) of the photo have the right to compensation,