For a long time, there has been confusion and ambiguity regarding the use of tires with M+S marking in the summer months in Italy. Motorrad published the following article in issue 14/2015:


Tires in Italy: No worries

A new regulation has made enduro riders heading for Italy considerably unsettled. Quite wrongly, as it now turns out: Anyone riding there in the summer months on M&S tires with a lower speed index than specified in the vehicle
than stated in the vehicle registration document has had to reckon with a severe fine of up to 1682 euros since 2014; in addition the vehicle can be immobilized immediately. Generally speaking the Italians are thus aiming for a BAN ON WINTER TYRES IN THE SUMMER. However, the issue with the speed index also applies to some enduro tires. A MOTORRAD inquiry police and tire manufacturers in Italy led to contradictory results. Italy led to contrasting statements. The supreme instance, the Italian Ministry of Transport in Rome, took a long time to answer, but finally stated: "Circolare no. 1049" only applies to cars, MOTORCYCLES ARE EXCLUDED. 
The statement is available in MOTORRAD.

Source: Motorrad from 26.06.2015 page 18 (14/2015)