from the daily "Il Resto del Carlino" of 27/03/2011 an article concerning what happened at an IBM premises the night before...
..The bomb was placed in a stairwell in the basement of the building housing IBM, at the level of the garage, near an electrical panel. The same complex houses the command of the Nas, but the offices are closed at night. In theory the area is only accessible to persons with keys or remote control, but the attackers may simply have taken advantage of a car leaving to enter the basement, only to disappear through a side door. The blaze started around 2.30, and the remote fire alarm went off in an operations centre in Milan. The signal was immediately sent to the supervisory institute La Patria, which sent its own patrol. The guards found the room filled with smoke and averted the fire brigade and police. When the smoke thinned, everything became clear. On one wall the attackers left the signature "Elf" with green paint. Investigators believe it is the acronym for Earth Liberation Front, a radical eco-terrorism movement known internationally, but it has not been specified whether they left any other references.
The main hypothesis is that the action falls within the campaign for the release of three anarchist prisoners in Switzerland. On April 15 it will be exactly one year since their arrest: Luca Bernasconi, Costantino Ragusa and Silvia Guerini, according to Swiss investigators, were preparing an attack at IBM and had Elf signed propaganda material. Already incendiary attacks on 6 October and 12 December against a repeater for cell phones and the Roadhouse Grill restaurant have been "dedicated" to them. These days, however, another anniversary that the anarchist galaxy recalls with particular devotion. At dawn on March 28, 1998 the squatter Edoardo Massari known as Baleno, suspected of terrorist acts against the high-speed rail, was found hanged in his cell at the prison of le Vallette. Another story of a past that always comes back.