The words "You're filming? Bravo", spoken by the woman to her lover in the video, have become a derisive joke online, and the phrase has been printed on T-shirts, smartphone cases and other items.
After a long court battle, she recently won a "right to be forgotten" ruling ordering the video to be removed from various sites and search engines, including Facebook.
But she was also ordered to pay 20,000 euros (NZ$30,000) in legal costs - a final "insult" which may have driven her to take her own life, according to several Italian media outlets.
"Why are these images still there? Why can people still mock and laugh at this young woman who ended her days because of this humiliation that she suffered?" wrote Naples daily Il Mattino on Thursday.
Prosecutors in Naples have opened an investigation into "incitement to suicide". The four men are being investigated for defamation.
The procession of the hearse carrying Ms Cantone's body was broadcast live.
The woman's family have called for justice and for to an end to shaming. "Now we call for the justice system to act so that her death was not in vain," the family said, quoted by Italian media.
The case has sparked fierce debate about in Italy on the "right to be forgotten" online.
"As a government, there's not a lot that we can do," said Prime Minister Matteo Renzi. "It's mainly a cultural battle - also a social and political battle. Our commitment is try to do everything we can... Violence against women is not an ineradicable phenomenon."
Two years ago, the European Union's top court made the groundbreaking decision to give people the "right to be forgotten" online, with internet search engines told to remove information deemed "inaccurate, inadequate, irrelevant or excessive" for the purposes of data processing, or face a fine.
In Britain, a revenge law came into effect in April last year, meaning those who share sexually explicit images without the subject's consent could find themselves in trouble.
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• Samaritans 0800 726 666
• If it is an emergency and you feel like you or someone else is at risk, call 111.