As protests erupted in Ferguson, Mo., following the fatal shooting of Michael Brown, many went to social media outlets for news and information, only to find that much content seemed to be missing from their streams.

Before reporters with national profiles arrived in Missouri, pictures of the militarized police presence in the area were circulating on Twitter, showing armed vehicles, snipers, rubber bullets and tear gas being used against protesters.

For those on Twitter, particularly people following journalists and community activists across the United States and Canada, the news about Ferguson was pervasive.  

Patrick Ruffini (@PatrickRuffini), a strategist with echeloninsight.com who specializes in digital analytics, tweeted a graph showing the rapid growth of posts on Twitter using #Ferguson on August 13.  His graph shows that the conversation grew from zero tweets to almost 4,000 within nine hours.

However, on Facebook a different trend emerged.

No Ferguson on Facebook

"My tweetstream is almost wall-to-wall with news from Ferguson.  Only two mentions of it in my Facebook news feed," tweeted Mark Hamilton (@gmarkham), a journalism instructor at Kwantlen Polytechnic University in British Columbia, on Aug. 13.

The post was quickly favourited and shared with hundreds of people, many echoing Hamilton's observations.

Zeynep Tufekci, an assistant professor at the University of North Carolina, Chapel Hill's School of Information and Library Science, was one of the leading voices online calling attention to this issue.

"No Ferguson on Facebook last night," she wrote in a post published on Medium on Aug. 14.

"I wonder: what if Ferguson had started to bubble, but there was no Twitter to catch on nationally?  Would it ever make it through the algorithmic filtering on Facebook."

Police Shooting Missouri

Police advance after tear gas was used to disperse a crowd in Ferguson, Mo., on Aug. 17. (Charlie Riedel/Associated Press)

Increasingly, people are using social media tools to raise awareness about local issues on national platforms, a practice called "clicktivism," said Dr. Anatoliy Gruzd, director of the Social Media Lab at Dalhousie University.

Hash tags are created to create a trend on Twitter and Facebook, but "there's a concern that the algorithmic filtering of the content can hinder the ability of the protesters to build awareness for their particular campaign," said Gruzd.

Commercial entities like Twitter and Facebook "have control of what we see on screens, how it's organized and what we might be interested in sharing," he said. And the algorithms that filter content on social media are proprietary, meaning that the public has no access to them.

"We don't know exactly what we're not seeing," he said. "The formula changes all the time."

Who decides the trends?

Police Shooting Missouri

A citizen peacekeeper tries to keep protesters back as police advance on Aug. 18, in Ferguson. (Christian Gooden/Associated Press)

The question is whether information is deliberately filtered by social media companies privileging some stories over others.

Fenwick McKelvey, an assistant professor in the Department of Communication Studies at Concordia University says the debate about how things trend on social media is not new.  A similar discussion took place about Wikileaks forcing Twitter to share information on how topics trend on its platform.

"Twitter Trends are automatically generated by an algorithm that attempts to identify topics that are being talked about more right now than they were previously," Twitter says on its official blog. "Sometimes a topic doesn't break into the Trends list because its popularity isn't as widespread as people believe."

Police Shooting Missouri

Police wait to advance after tear gas was used to disperse a crowd on Aug. 17 in Ferguson. Images of police in full military gear with armoured vehicles have been among the most widely circulated media from Ferguson. (Charlie Riedel/Associated Press)

Who's the villain?

"I don't think there's a villain," McKelvey said.

"We want social media to behave like a journalist," he says, because we are turning to social media more frequently for our news.

According to McKelvey it's not an editorial bias that dictates what appears or doesn't appear on our timeline. It's algorithms intended to help us get a personalized experience on the web.

Facebook relies on strong connections, pushing content from friends that you regularly interact with and material that you have previously shown interest in to the top.

If you have a habit of liking cat photos and watching cat videos, Facebook will push cat content to the top of your stream.

In contrast, Twitter is a more open discussion that relies less on individual connections, allowing more interactions between strangers, and basing trends on popular topics discussed in your geographic area rather than among your social circle.

Policing the internet

"The government plays a big role in bringing accountability to these companies," said McKelvey, mentioning user privacy, data security and fair pricing as examples.

He says given the size and influence of these social media sites it's time to go further and demand more transparency that allows users greater control over how and what information is presented to them.

"Media has power and new media has power that has not been met with sufficient regulations."