The Court of Cassation did not upheld the recourse against the application of preventive measures brought by some foreigners indicted with the offense of ‘participation in terrorist associations’; an offense provided for in Article 270 bis of the criminal code. The Court took the same interpretive approach of its previous decisions and, thus, confirming that this offense, though not consists in mere psychological stance, can result from proclaimed adherence to terrorist associations, if joined with concrete possibility of action and effective dangerousness. These are criteria of broad application as far as so-called offenses “of supposed danger” are concerned. In the case, the accused persons had carried out preliminary activity – such as terrorist propaganda, proselytism, training and self-training – sufficient to prove a) the creation by them of a jihadist cell in Italy and b) the not only ideological participation of this cell to the Islamic State’s terrorist programme.