Thanks for the information, Marc.
The question may have been asked incorrectly from a legal viewpoint. Photographs can usually be made without violating any laws. However, the question is: can they be licensed, distributed and edited freely?
From WM-IT people who organized this competition received an email indicating the legal questions surrounding the Italian legislation: known the doubt we will get in touch with the councill of Alghero and the council's attorney has assured us that the photographs of the monuments does not violate any law and that could be made freely.