What did we want? That everything changed [...] that universities were to be collectively managed, that there was no selection, that the Vietcong won the war, that culture changed, but most importantly that this extraordinary movement, that changed our daily life, could stand up.
With Piperno and Toni Negri, he founded Potere Operaio in 1969. On 7 April 1979 he was arrested, along with Negri, Piperno and others members of the autonomist movement, and accused of planning armed attacks and plotting to overthrow the government. In 1981 he managed to flee first to Denmark, then to Paris, where he remained protected from extradition thanks to the Mitterrand doctrine. Scalzone revealed that his escape was helped by actor and friend Gian Maria Volonte. In 1983 he was sentenced to 16 years' jail, reduced to nine in 1989. While in France, Scalzone worked for a political solution to the "Years of Lead" that could lead to an amnesty to political refugees and prisoners.
In 1998 he briefly and secretly came back to Italy passing through Corsica: a photographic service by the newsmagazine L'Espresso later revealed the episode.
A 17 January 2007 ruling of the Court of Milan declared his crimes ("subversive association and member of an armed organization") prescribed. He announced he had come back to Italy to "fight, under new conditions, an old battle".