It is interesting that you folks mentioned google.it as I too see a lot of referrals from it in my logs this week.Some time ago it was philipinnes (where the language is English) and many here had reports of unusual traffic from google.ph
Why the hell does Google show an English language website on google.it? I know they have a translator engine but still...and on top of it they are said to measure and weigh user and usage metrics post panda. If they are going to drive unnatural traffic like this, as I said earlier, your metrics are bound to be screwed.
All these metrics would make some sense if they are measured and weighted at the level of the building block (i.e.keywords) and not at the page or site level. They currently seem to be aggregating them at the site level.