Some time ago, I linked a nice tool that provided custom-made demographic reports about Facebook users, updated in real time. I discovered that the tool does not work anymore, so here is a link to a site where you can find Country-by-Country data, grouped by genre and age group.
Apparently, the leading group in Italy is 25-34 (29.1%): but the span of this group is 10 years, so it should be compared to the sum of two other (younger) ones, i.e. 14-17 and 18-24, scoring together an impressive 37.7%. Nonetheless, it's enough for me to say that Facebook is definitely not just "a toy for kids" – especially considering the fact that almost 30% of the total population is above 35 years.