Social media companies scrambled to deal with a case of viral content gone wrong, when a former Virginia broadcaster shared video on Facebook and Twitter of himself killing two journalists during a live television broadcast. Video of the incident quickly spread online, triggering a flood of disturbing content reports and sending moderators rushing to erase the shooter's social media presence.

Twitter, Facebook and LinkedIn accounts belonging to Bryce Williams, the on-air alias of shooter Vester Flanagan, were quickly taken down in the wake of the shooting. However, before Flanagan's accounts went offline, many had already saved and shared the videos and messages he posted, making it hard to rein in completely. The video was easy to find on Twitter and Reddit through much of the day, before moderators clamped down on it. All the while, Twitter saw a heated debate between those seeking to make Flanagan's video available to others, and those wanting it removed out of respect for the victims.

The whole incident was a rare case of social media playing a prominent role in a high-profile crime, and it raised many questions online about what content we share and how it should be monitored.

Jeffrey Dvorkin, head of the University of Toronto's journalism school, said social media has made it harder to filter offensive content out of our daily lives.

"Social media has created a more democratic media culture, and that's a great thing, but it's also a bad thing because it can be a race to the bottom to get those (offensive) pictures first," he told CTV's Canada AM on Friday.

Dvorkin added that professional journalists aren't the only ones responsible for that "race to the bottom." Citizen-journalists also play a big role in spreading disturbing content like the Virginia video online.

However, all social media users have the tools to slow the spread of offensive content, using the social networks’ built-in reporting tools.

Facebook and Twitter each have content guidelines restricting "offensive" or "inappropriate" material. However, considering the volume of tweets and status updates each day, Facebook and Twitter can't police everything before it goes online. Instead, they're forced to rely on their users to report inappropriate, violent or potentially criminal content, using tools built into their sites.

When a post is flagged as inappropriate, it is immediately flagged to a team of moderators for review. At Facebook, the company employs hundreds of moderators working in shifts at four different centers around the world to address all their content complaints, spokesperson Meg Sinclair told CTVNews.ca. These moderators work a lot like battlefield doctors, sifting through each case presented to them and prioritizing them based on severity. This triage approach allows them to address the most urgent and potentially dangerous cases first, such as suicidal rants, bullying or videos showing crimes. Facebook also works with law enforcement when it identifies potentially criminal activity.

The Facebook spokesperson said context is very important when it comes to judging potentially offensive content. For instance, a violent video posted as a helpful warning to others might be acceptable under Facebook's content guidelines, perhaps with a graphic content warning included. However, a video that boasts about a crime or victimizes someone else would not be considered acceptable.

Twitter addresses flagged content in a similar way. "After you flag someone else's media, the Twitter team will review and determine if that media requires a warning message in order to comply with Twitter's Media Policies," the company says on its media policy website.

Anatoliy Gruzd, an associate professor at the Ted Rogers School of Management, says people should take a role in helping to stamp out offensive content online.

"We want to share information, and social media platforms make it easy for us to do so," he told CTV's Canada AM on Friday. However, he said everyone should recognize the impact of choosing the share something like the Flanagan murder video.

"We need to think twice as social media users before hitting that retweet button," he said.