The hack was made possible due to an infection by a variant of the Rbot worm, a backdoor Trojan, which can surrender control of key systems to a hacker.
Italian politics is regarded in some quarters as a bastion of homophobia, with certain recent events stoking that particular fire. Firstly there was the debacle when Rocco Butiglione, Italy's candidate for European Union Commissioner, branded homosexuality a sin, and secondly the sacking of Senate vice-president Dario Mattiello after he was pictured at a gay night spot in Rome.
Now it is appears a pro-gay group or individual may be striking back.
According to reports the upper house of the Italian Senate in Rome ground to a halt as it was hit by the worm. Following the infection images of hardcore gay pornography started to be displayed on screens around the building.
Graham Cluley, senior technology consultant for Sophos, said it is impossible to be sure of the motivation behind the attack, unless the culprit is caught or confesses.
Cluley added: "Whatever their motives, hackers have shown a bare-faced cheek by planting these homosexual images at the heart of Italy's political establishment."