Popular community website Reddit has been at the center of a contentious debate in recent weeks. Thousands of users revolted when the site shut down five of its most controversial discussion channels that encouraged hate for blacks, homosexuals and overweight people.

Community backlash was so strong, the site’s interim CEO, Ellen Pao, stepped down. Pao defended her decision to close the channels in an op-ed that appeared in the Washington Post Thursday. In it, she talks about the challenges of curating conversations on the web, while censoring hate speech and harassment.

She also pointed out how quickly threats on the web can turn into real life intimidation and silencing.

Abuse can be found in forums and comment sections across social media. It’s called "trolling." As more people continue to come online, forum moderators are working to strike a balance between free discussion and making comment sections safer.

Enter computer scientist Jennifer Golbeck, who has done extensive research on Internet trolling. She says site moderators are up against people who take joy in creating chaos.

“There’s research that has done psychological profiling on people who say they enjoy trolling as their main online activity. They tend to score really high on measures of sadism, narcissism, [and] psychopathy. They essentially enjoy destroying nice things that other people have set up, and they really find entertainment in that,” she said.

To hear more about the future of open forums on the Internet, press the play button above.