Sicily was once Muslim. Continental Southern Italy never was, except for a few brief occupations of coastal cities.

Most European countries are awake to the threat of Islam (I would say that Sweden, Norway, Belgium and to some extent Britain and the Netherlands are still in denial). They tend to deal with it mainly as a matter of internal security, on the assumption that the immigration from the third world cannot really be stopped; but action is being taken, and in this field, incidentally, the French have been blazing the way. At any rate, Islam is not the only threat, as has been shown by the recent Chinese riots in Milan and the incredible behaviour of the Chinese government.