Just two informations on this: the trial is opening; Google's exec was silly enough to travel to Italy for a conference and got arrested.
I can't find information about which bits of the criminal code or legislation has been used, but my knowledge of Italian is too bad to do any serious research.
For the International Association of Privacy Professionals, "Additional claim filed against Google" (3 February 2009)
Update on 21 February 2009:
I thought it was not worth writing a different post, but rather completing this one. The judge seems to have refused dismissed the case. Assuming that Google is not responsible, two interpretations can be given: 1) a silly decision, 2) a willingness to let the trial happen so that the flaws in the prosecution's arguments can be exposed and the judgment be a final stop to this king of charges. The later is not as unlikely as one may think and it is a tool used by European Governments themselves when they let a case move to the European Court of Human Rights knowing full well they will be condemned. It is an effective way of settling the law.