According to the following page, races are getting cancelled at Monza, due to a court decree. Silencers would have to be fitted for cars or bikes to race on the track...
Click here to sign the petition: http://www.petitiononline.com/m0nz4/petition.html
Here's a translation:
To: Tribunal of Milan
MONZA RACES CANCELLED BECAUSE RACE CARS ARE TOO NOISY!
Expecting final decision of the Tribunal of Minal regarding the noise related to racing at the Monza track, [...] the Milano Automobile Club and the Sias have decided to cancel [...] races that were to take place on the week-end of the 19th of March.
Cancellation has been made necessary due to the November order by the Tribunal of Milan [...] (suspension of use of any vehicle not fitted with a silencer) [...].
In consequence the following races will not take place: Italian Touring Championship, Italian F3 Championship, Italian Proto Championship, Cadet Trophy Junior Monza, Superstars Trophy, F3000 Italia Championship.
Let's try to save that track, OUR TRACK, let's be many!