The 31-year-old was found hanged Tuesday at her aunt's home in Mugnano, near Naples, in the south of the country, according to media reports.
Four people are under investigation by criminal prosecutors over alleged defamation of the woman, Italian state media ANSA reported.
Cantone sent the video to friends, who published it online without her knowledge, ANSA said. More than a million people watched it, and she became the target of abuse.
The phrase "You're filming? Bravo," which she says to her lover in the clip, went viral online and was printed on T-shirts, smartphone cases and other paraphernalia.
Cantone attempted to escape the growing attention, leaving her job and moving to Tuscany, where she tried to change her name, ANSA said.
Surrounded by mourners, Cantone's mother said her daughter was a " very good girl" outside a church Thursday as she touched the coffin at the funeral, which was broadcast live on Italian television.
After a long court battle, Cantone won a "right to be forgotten" ruling that ordered the video's removal from websites and search engines, including Facebook.
In 2013, the European Union ruled that people should be given the "right to be forgotten" online,
with Internet search engines ordered to remove information deemed "inaccurate, inadequate, irrelevant of excessive" for the purposes of data processing -- or be hit with a fine.
Still, Cantone was ordered to pay 20,000 euros ($22,500) in legal costs, which local media have called a "final insult."
"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?" the Naples newspaper Il Mattino asked Thursday.
The case has led to widespread discussion of the rule in Italy.
"As a government, there's not a lot that we can do," Italian Prime Minister Matteo Renzi told reporters.
"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."