When 25-year-old Caitlin Seida dressed up as Lara Croft from the movie Tomb Raider one Halloween, she posted a picture of herself enjoying the night's festivities on Facebook. At most, she figured a few friends might see the photograph and comment.

The picture remained in Seida's social circle for more than three years. Then one day in 2013 a friend sent Seida a link with a cryptic note: “You're Internet famous.” Clicking the link took her to a site called the International Association of Haters, where her Halloween photo—which she had posted publicly by mistake—bore the oversized caption “Fridge Raider.” Hundreds of commenters dragged Seida through the mud for wearing a skimpy costume while being overweight. “Heifers like her should be put down,” one commenter wrote. “What a waste of space,” another piped in.

Horrified, Seida did some more quick searches and realized her photo had gone viral, racking up poisonous comments on dozens of sites. Reading the messages was like absorbing a series of body blows. “I felt like shit,” Seida says. “I cried and cried and cried some more.” With a paralegal friend's help, she contacted Web site owners to get the offending images and posts taken down, but she knew her efforts would likely fall short. “I can herd cats more easily than I can control what's posted online.”

Despite the publicity devoted to teenage cyberbullies, online aggression is hardly confined to the high school set. About one in four adults has been cyberbullied or knows someone who has, according to a recent poll by the online design firm Rad Campaign, along with Lincoln Park Strategies and Craigslist founder Craig Newmark. The abuse can come in the form of insulting e-mails, tag team–style pile-ons in Internet forums or personal attacks in news article comment sections. Victims are often so profoundly affected that they descend into depression or even contemplate suicide. Yet the problem has largely gone unaddressed because so few observers take it seriously and because it can be unclear which comments qualify as bullying. “People are reluctant to report it,” says Chris Piotrowski, a cyberbullying expert and research consultant at the University of West Florida. “A lot of them feel like, ‘[If] I go to the police, what are they going to do?’”

Researchers are uncovering the psychological forces behind such poisonous verbiage and the harm it causes, and their work points to ways of preventing vicious avalanches of verbal aggression—or at least minimizing the damage. An important part of the solution involves all of us. As members of the Internet democracy, we each have the power to redirect negative group tendencies in ways that promote online civility. “Don't wait for the other two or 300 [people] to do something,” says Mary Aiken, director of the CyberPsychology Research Center at the Royal College of Surgeons in Ireland. “It's up to users to create a better environment.”

“They got the better of me, and they won”

The trope of the swaggering bully is almost as old as human history. Whether children or adults, bullies blast their targets with scathing words and profane put-downs—and they do not let up, even when the victim begs for mercy. Bullying behavior probably has evolutionary roots, argues social anthropologist Christopher Boehm of the University of Southern California. Early humans who were good at lording it over others enjoyed a boost in their social standing, and as a result, they produced more offspring.

Contrary to popular wisdom, bullies are not merely compensating for their own low self-esteem. In a 2013 study of thousands of middle school students, psychologist Jaana Juvonen of the University of California, Los Angeles, and her colleagues found that bullies are often perched at the top of the social hierarchy and demean others to cement their position. Upbringing also plays a key role: according to social learning theory, we learn how to interact with others by observing those close to us. Aggressive parents and other role models, then, may produce aggressive kids. The fallout can be devastating: bullying victims suffer significant distress, sometimes for decades. The U.S. Secret Service reports that in most school shooting incidents, shooters felt persecuted or bullied before launching their attacks.

Now that people are socializing in virtual realms, an age-old dynamic has taken hold in a new environment. Cyberbullying is usually defined as intimidation, hurt or harassment conducted using cell phones, the Internet or other electronic devices, but as Piotrowski points out, the contours of this definition are somewhat blurry. “What defines cyberabuse? To one person, it's someone who's being rude. To another person, it's an offensive statement. Another person might say it's [an attack that's] escalating.”

At its most obvious, cyberbullying is extremely brutal. Women's-rights activist Caroline Criado-Perez endured dozens of unhinged online trolling attacks from woman haters after she convinced the Bank of England to feature Jane Austen on its 10-pound note. “I remember the man who told me a group of them would mutilate my genitals with scissors and set my house on fire while I begged to die,” Criado-Perez told the New Statesman in January. “I remember the fear, the horror, the despair. I remember not being able to sleep. I remember thinking it would never end.” (Although Criado-Perez did contact the police, she felt they did not take her complaints seriously.)

As Criado-Perez's experience suggests, online persecution can take an outsize toll on mental health. Victims of cyberabuse often show symptoms consistent with post-traumatic stress disorder, including flashbacks, runaway anxiety, guilt or depression. They report low self-esteem and feelings of helplessness. “It's a serious problem that has serious psychological consequences,” says social psychologist S. Alexander Haslam of the University of Queensland in Australia. Even people used to the public eye may reach a breaking point when tormentors go too far. Australian journalist Charlotte Dawson—herself an antibullying activist—broke down earlier this year after absorbing a relentless barrage of Twitter messages mocking her depression and encouraging her to kill herself. She was found dead in her Sydney apartment, where she had hanged herself. “It just triggered that feeling of helplessness when the trolls got to me,” Dawson said in a 2012 interview on Australia's 60 Minutes after a previous round of Twitter attacks. “They got the better of me, and they won.”

Mob Mentality

Just like real-world bullies, the worst online gangsters often display antisocial personality traits. Some may show characteristics of psychopathy such as aggression and disregard for fellow human beings; others are sadistic. In a 2014 study psychologist Erin E. Buckels of the University of Manitoba and her colleagues surveyed more than 1,200 Internet users and found that those who agreed with statements such as “I enjoy making jokes at the expense of others” and “I enjoy playing the villain in games and torturing other characters” were more likely to show traits associated with personality disorders. It stands to reason that people who have real-life antisocial tendencies might show similar contempt for others in the online realm.

Still, plenty of psychologically balanced adults take online potshots at others, says psychologist John Suler of Rider University, partially because cyberspace lets them create a virtual persona that is separate from their everyday identity. They know that when they retreat behind the cloak of anonymity, they probably will not have to answer for their actions. The phenomenon of the faceless, nameless online bully is a familiar one; surveys suggest only about one in four online bullying victims know their attackers in real life. “From the abuser's point of view, [online bullying] is low risk, high reward,” Piotrowski says. “They're thinking, ‘I won't get caught because it's online,’” and they get the buzz of feeling elevated because they are pushing someone else down. In a 2012 study psychologists Noam Lapidot-Lefler, now at the Max Stern Academic College of Emek Yezreel, and Azy Barak of the University of Haifa instructed participants to debate a contentious topic in pairs over online chat; they noted that people were more likely to threaten their debate partners when posting under an alias than when using their real names.

But the most noxious and prevalent instances of online bullying emerge from a combination of anonymity and group forces. In 2001 social psychologist Tom Postmes, now at the University of Groningen in the Netherlands, and his colleagues reported that when online participants were anonymous, they were more likely to conform to the behavior of the groups they belonged to—a tendency that is problematic when the group's members are rude or aggressive. Similarly, in a 2012 study psychology researcher Adam Zimmerman of the University of North Florida studied 126 online participants in a word-unscrambling game and found that those who did not use their real names were more likely than identified participants to write aggressive blog posts about their fellow players, especially when they observed other participants acting aggressively. “We get permission [to bully] from the people around us,” Zimmerman says. “It gives us the idea that we could also do that if we want to.”

When nameless, faceless online participants assume the identity of the group that surrounds them, a virtual mob mentality takes hold. People are impulsive and aggressive and tend to copy one another, often leading to tag-team attacks like those hurled at Seida. “When people engage in online bullying, they are often doing it in front of a particular audience they imagine is approving,” Haslam says. If a chat forum's terms of engagement—stated or unstated—allow people to be bullied without consequence, new participants are probably going to conform to the norms set by the bullies. Even people with good intentions can succumb. “If others are piling on someone, you might join in even if you weren't setting out to hurt anyone,” adds psychologist Scott O. Lilienfeld of Emory University.

Once insult-slinging gets under way in a chat room or e-mail thread, it can escalate quickly, perhaps because empathy is more elusive in a virtual environment. Cyberaggressors cannot see their victims' tears or the fear in their eyes. Their targets are abstractions. In addition, the bullying persists in ways that would have been unthinkable in the era before Google and Facebook. Victims relive that punch-in-the-gut feeling every time humiliating photos of them appear on a new Web site or insults appear in search results for their name. Also, as Seida learned, erasing the attacks or even getting bullies to admit to the harm they have caused is fiendishly difficult. When Seida and a friend tracked down some of her tormentors and sent them personal notes, they were rebuffed. “We sent them messages and a little certificate that said, ‘Why don't you be a human being and take down the comments you made?’ Nobody apologized.”

Bullying can affect bystanders, too. In a study published in 2013 Colorado State University communications specialist Ashley Anderson and her colleagues recruited more than 1,000 people to read an online article about the risks and benefits of nanotechnology. Readers who were exposed to “flame wars” in which commenters slammed nanotech or insulted its defenders tended to see nanotechnology's risks as more pronounced than did readers who had not seen such verbal attacks, regardless of whether the arguments held water. If, as these results suggest, bullies' comments are often persuasive, passive observers might start to buy into some of the attackers' claims (“Theresa is a slutbag ho”).

Setting New Norms

The toxic fallout from online attacks has led some respected news outlets to kill off virtual discussion communities. “We are as committed to fostering lively, intellectual debate as we are to spreading the word of science far and wide,” wrote Popular Science's then digital editor Suzanne LaBarre last fall, announcing that the magazine planned to eliminate its Web site's comment section. “The problem is when trolls overwhelm the former, diminishing our ability to do the latter.”

The decision by Popular Science to nix online comments provoked outcry. Efforts to curb online bullying and flame wars often err in the direction of limiting open discussion. Part of the reason is practical. Policing individual online interactions—by, say, enforcing language restrictions on discussion boards or cleaning up news comment sections—can be a time-consuming task for Web site managers. What is more, few victims report bullying to site administrators because they think nothing will be done about the problem or because they fear retribution from attackers.

So far legislative solutions to the online aggression problem do not seem all that effective, even though 48 states have laws against electronic harassment. California's legal code, for instance, gives administrators grounds to suspend or expel students for participating in online bullying, and Louisiana's legal code reads, “Whoever commits the crime of cyberbullying shall be fined not more than five hundred dollars, imprisoned for not more than six months, or both.” Such laws, however, are seldom enforced, in part because cyberbullying victims do not always report being abused—and when victims do complain, administrators and discussion board owners do not always notify state authorities.

In the absence of systematic policing by Web site managers or the government, some administrators have begun testing automated antibullying tools. A system produced by the video game company Riot Games, for instance, detects patterns of negative behavior from particular online players and sends them a quick message, gently letting them know they have crossed a line. “For neutral and positive players,” Jeffrey Lin, a lead designer at Riot, told GamesIndustry magazine, “this subtle nudge is often enough to get them back on track.”

Yet some hard-core bullies are unfazed by automated warnings and keep right on unloading their venom. In such cases, community members should step in—whether by writing a response to the aggressor on the forum or reporting bullying comments as abuse. When members of an online forum, discussion group or e-mail thread consistently refuse to tolerate bullying, new participants will probably conform to that established norm, turning the group into a force for good.

All online participants determine what a community's norms are. “If trolls show up, if the community as a whole can say, ‘This is not something we want here,’ it can convince that person to move on,” Suler says. Taking a stand not only helps the victim but is also good for you: when people see others being bullied and fail to speak up, their own psychological health often suffers.

Concerned onlookers can also help curb bullying's spread by reaching out to victims individually via e-mail or direct message. Aggression often begets aggression—cyberbullying victims may turn around and bully others, according to San Diego State University psychologist Jean M. Twenge. But you can mitigate this effect by offering the abused your support and condemning the attacks. In a 2007 study Twenge and her colleagues found that when people made a short, friendly connection with someone else following an episode of social exclusion, the victim was less likely to show aggression afterward. “Having even one person accept you seemed to mitigate the [aggression] effect,” says Twenge, author of Generation Me. “Reach out and say, ‘I'm sorry this happened.’”

Such outreach is especially crucial because even antibullying education may not deter determined trolls. According to a 2013 study by University of Texas at Arlington criminologist Seokjin Jeong and Byung Hyun Lee of Michigan State University, students were more likely to be bullied at schools that had installed antibullying programs, perhaps because the programs inadvertently gave bullies ideas for tormenting their victims.

Rallying Friends

Many months after enduring online ridicule, Seida decided she was not going to let the bullies' vile comments define her. To give her detractors the middle finger, she did a boudoir photo shoot while wearing the now infamous Lara Croft costume. “If they're going to talk, I might as well give them something to talk about!” she says.

Seida's brush with cyberbullies inspired her to reach out to others on the receiving end of vicious online attacks. Along with a photographer friend, she created ifeeldelicious.com, a site designed to help victims of online bullying repair the damage to their dignity and psyche. She and other members ran a successful campaign against a notorious bully they called “the King of Mean,” rallying others to boycott and speak out against his insult-ridden Web site and social media sites. She advises people who face relentless online jibes to gather a group of friends who appreciate them. (For additional advice, see “What to Do If You're a Victim,” on page 51.) Indeed, knowing someone else has your back goes a long way toward softening the impact of drive-by online attacks. “Talk to somebody—find a support system,” Seida says. “If you keep it inside, it's just going to eat you alive.”

What to Do If You’re a Victim

If you have suffered abuse at the hands of cyberbullies, you are not alone. Millions of others have, too. Here are some expert-approved strategies to stop the harassment and minimize its effect on you. —E.S.

Don’t engage. When the harassment is relatively mild, the old “I can’t hear you” approach really can work. Block the person’s social media profile or just stop replying to the comments. The troll wants you to get worked up. When you don’t respond, he or she sometimes loses interest.

Alert those in charge. Report abusive messages that include ad hominem attacks or vulgar language to someone who can make them stop—whether the police or an online forum’s administrator. A 2014 survey found that in 61 percent of cases, social networks shut down reported harassers’ accounts.

Talk to a professional. If online attacks are bad enough to make you seriously doubt your self-worth, consult a therapist. Cyberbullies are skilled at eliciting a very intense, instant reaction that may be unlike anything else you have experienced. You most likely will need support to deal with it.