Often there is little comeback for victims but in Australia Twitter is being sued in a twist of online defamation.
Television personality Marieke Hardy is the victim of a "hate blog" called "Marieke Hardy is Scum" but she fought back by exposing on Twitter who she thought was behind the site.
Unfortunately, she named the wrong person. She has settled with that person and has apologised - and now he is suing Twitter, where her accusation about him appeared.
Nothing is sacred online, as a documentary which screened in Britain last month shows.
In an Anti Social Network, broadcaster Richard Bacon goes after an internet troll - a person who deliberately makes inflammatory comments or posts - who has targeted him with worsening abuse for years, and also explores the disturbing world of RIP Trolling, where people go on to tribute sites and abuse the dead.
Two Englishmen have so far been jailed for such offensive behaviour.
A psychologist who specialises in the internet, Nate Gaunt, says online hate is alive and well in New Zealand.
People often do it because they can, he says, and New Zealand has as many offenders as anywhere.
"We have people posting things about each other, email bombing, text bombing, text bullying is a big problem... people posting compromising pictures of ex-partners, people hijacking others' websites and Facebook pages and posting things. Most definitely, it's happening here as much as anywhere else."
Two recent examples emerge out of Dunedin. In April online trolls infiltrated the Dunedin Buy Sell and Trade group's page, copied photos of people's children and threatened to post them on child porn sites.
Group moderator Alice Hudson says while the trolls mostly tried to sabotage people's sales and trades, some of them targeted individuals "and the things that were said were sickening".
A week ago a bar manager considered legal action against another bar owner, saying the man had posted offensive and homophobic comments about him on Facebook.
Benjamin Hanssen of the Monkey Bar told the Weekend Herald he had decided against defamation action because it was so expensive.
The other bar owner, who had posted about "faggots" and Aids, did not return our calls.
Hanssen says the comments were posted on the man's own Facebook site, which is linked to his nightclub and bar site. "It went viral and I mean that literally. It went all over the place..."
Hanssen says he is a 40-year-old educated male and can handle himself, but for others with sexual identity issues such attacks can range from damaging to catastrophic.
Gaunt says when online, people can act in a way which they would not ordinarily. This is called disinhibition.
There are some good sides to that, where people may try out different aspects of their personalities and be a bit bolder, but sometimes people can be so disinhibited they become hateful or harmful.
Sometimes, because of the immediacy of the internet, they don't have time to reflect about the consequences. And sometimes there is a sense of distance between the internet and the person and their victim.
"That means we'll probably be a bit more willing to press the button than we would to say something out loud, there isn't the same kind of fear of immediate retaliation," he says.
Martin Cocker from Netsafe, an organisation that promotes cybersafety, also says because you can't see the damage, bullying or nasty commenting tends to be extreme online.
There are laws which exist and which can be used, such as the defamation law, but they are not used very often - if someone defames you from another country then you would have to take a court case against them from that other country, he says.
While there is no real way of stopping the abuse, understanding the technology helps.
"The more technically literate you are and the more understanding you have of the technology environment the more likely you'll be able to manage a solution."
People are not necessarily nastier than they were, he thinks, but there is an increasing use of technological complexity.
"If there's a newness to it the difference is the people who are doing it now - trolling - tend to be the more technically capable ones. Maybe in the past nerds wouldn't have been so likely to be bullies but now nerds are the ones with the power.
"All the same tools that are making it convenient and fun to produce scrapbooks or videos about the family are also enabling bullies to be more vicious in their attacks."
Blogger and political commentator David Farrar reckons the ability to post anonymously removes the shackles of responsibility, because anonymous people don't have to worry about their name coming up in the google search engine.
Farrar set up the site Kiwiblog and blogs six to eight times a day, getting hundreds of comments a day.
"You do get some quite startling displays of sometimes visceral hatred online. What I've found unusual, too, is that sometimes I've met some of these people at drinks and they actually in real life can be quite mild-mannered, you know, they're not a sort of psychotic axe-murderer."
He has also had abuse aimed at him, including a couple of death threats over the years, one of which went to court, and a few years ago someone set up a different Kiwiblog site which was devoted to criticising him and the real site.
On his blog, he often finds the worst abuse after a thread has gone to 10 or 15 responses and the best way to stop it is to not engage or things can get out of hand.
"Recently I had a couple of people on the David Bain thread threatening harrassment orders against each other."
The Law Commission has been taking a look at the adequacies of the law for this era of digital advancement and among recommendations is a tribunal which can award compensation, or the appointment of a commissioner.
Farrar has some concerns about a tribunal because there are people who will try to use any part of the complaints process to shut down people they don't agree with, so reputable sites may get hammered by ideological opponents and spend all their time defending themselves.
But he does like the idea of a tribunal being able to make findings as to whether something is true or not.
"When untrue things are said about people and they come up in Google, that is a real problem."
Most people don't want a two-year court battle to get damages, but an independent service which is trusted which could give a statement finding something to be untrue would be valuable because that, too, would turn up in a Google search.
