Pressure is growing on social networks to play a bigger role in finding and weeding out jihadists and others looking to recruit members and plot deadly attacks.
But it's more complicated than it sounds: networks like Facebook and Twitter support free expression, and filtering our bad actors is challenging both from a technical and civil liberties perspective.
Still, US and European officials are pressing social media to do more following deadly attacks over the past few weeks in Paris and southern California which have been linked to supporters of the Islamic State organization.
A White House statement earlier this month called for "a dialogue" with Silicon Valley and others on the subject, saying more should be done "when the use of social media crosses the line between communication and active terrorist plotting."
The European Commission has also called for dialogue with the major social media networks.
And France passed emergency measures that could shut down websites or social media accounts which encourage terrorist actions.
Concerns have been rising amid increased presence on social networks of radical groups that seek to recruit fighters and communicate for planning.
FBI Director James Comey said the Islamic State organization, also known by the acronym ISIL, "has persistently used the Internet to communicate, and its widespread reach through the Internet and social media is most concerning."
Comey said that through social media, "the message of radicalization spreads faster than we imagined just a few years ago."
In Congress, Senators Dianne Feinstein and Richard Burr proposed legislation to require online communications services to report potential terrorist activity.
"That information can be the key to identifying and stopping terrorist recruitment or a terrorist attack, but we need help from technology companies," said Feinstein, from California.
Consequences for freedom
But it remains to be seen how much can be done by networks designed for sharing updates and which have hundreds of millions of users. And some say even if they could help in the fight against radicalization, the civil liberties price would be too high.
"Having government pressuring, or encouraging companies to do more, carries with it a lot of consequences for individual freedom," says Emma Llanso, a free speech specialist at the Center for Democracy and Technology.
An open letter from technology organizations including the Internet Association, which represents major social networks, warned of the negative consequences of the proposal known as the Requiring Reporting of Online Terrorist Activity Act.
Such a law "would impose a new government mandate requiring a broad spectrum of companies to report users' activities and communications to the US government, ultimately not achieving national security gains," the letter said.
The proposal "risks chilling free speech, including counterterrorism speech, and also chilling innovation" and "it contradicts and undermines 20 years of federal Internet policy that remains the legal foundation of the Internet's transformative role in promoting democratic values and free speech worldwide."
Although online companies are able to detect and report child pornography using algorithms and a database of inappropriate content, applying this to terrorism is more challenging.
"Millions of pieces of content are received every day, making the idea of proactive monitoring and viewing before posting and uploading completely impossible," Llanso said.
Social media groups say they already do what they can to avoid being used to spread hate and violence.
"There is no place on Facebook for terrorists, terrorist propaganda or the praising of terror," said Monika Bickert of the world's biggest social network, saying it employs a global team which works around the clock in numerous languages for monitoring.
"Our community standards make this clear, and we work aggressively to ensure that we do not have terrorists or terror groups using the site."
Twitter says it has a similar policy and also actively monitors its network.
"Violent threats and the promotion of terrorism deserve no place on Twitter and our rules make that clear," a spokesman said.
The video-sharing service YouTube, owned by Google parent Alphabet, "has a strong track record of taking swift action against terrorist content," a spokesman said.
"We have clear policies prohibiting terrorist recruitment and content intending to incite violence and quickly remove videos violating these policies when flagged by our users. We also terminate accounts run by terrorist organizations or those that repeatedly violate our policies."
But mandatory legislation raises a risk that social media firms will overreport to remain in compliance, said Sophia Cope of the Electronic Frontier Foundation, and in doing so raises suspicion on many law-abiding citizens.
"These people will be under the cloud of government suspicion for exercising their First Amendment rights," she said.
Michael Beckerman, president and chief executive of the Internet Association, agreed, saying the Burr-Feinstein measure would lead to "a vague and unworkable standard for reporting and a massive new liability regime that could chill free speech and innovation online.
He added: "The legislation incentivizes Internet platforms to overreport, even poor quality information, to authorities, making it more difficult to find credible threats."
Explore further: Lawmakers want social media companies to report extremists (Update)