NEW YORK -- Facebook is stepping up its efforts to keep inappropriate and often violent material -- including recent high-profile videos of murders and suicides, hate speech and extremist propaganda -- off of its site.

On Wednesday, the world's biggest social network said it plans to hire 3,000 more people to review videos and other posts after getting criticized for not responding quickly enough to murders shown on its service.

The hires over the next year will be on top of the 4,500 people Facebook already tasks with identifying criminal and other questionable material for removal. CEO Mark Zuckerberg wrote Wednesday that the company is "working to make these videos easier to report so we can take the right action sooner -- whether that's responding quickly when someone needs help or taking a post down."

Facebook, which had 18,770 employees at the end of March, would not say if the new hires would be contractors or full-time workers. David Fischer, the head of Facebook's advertising business, said in an interview that the detection and removal of hate speech and content that promotes violence or terrorism is an "ongoing priority" for the company, and the community operations teams are a "continued investment."

Videos and posts that glorify violence are against Facebook's rules, but Facebook has drawn criticism for responding slowly to such items, including video of a slaying in Cleveland and the live-streamed killing of a baby in Thailand. The Thailand video was up for 24 hours before it was removed.

In most cases, such material gets reviewed for possible removal only if users complain. News reports and posts that condemn violence are allowed. This makes for a tricky balancing act for the company. Facebook does not want to act as a censor, as videos of violence, such as those documenting police brutality or the horrors of war, can serve an important purpose.

LIVE STREAM CHALLENGES

Policing live video streams is especially difficult, as viewers don't know what will happen. This rawness is part of their appeal.

While the negative videos make headlines, they are just a tiny fraction of what users post every day. The good? Families documenting a toddler's first steps for faraway relatives, journalists documenting news events, musicians performing for their fans and people raising money for charities.

"We don't want to get rid of the positive aspects and benefits of live streaming," said Benjamin Burroughs, a professor of emerging media at the University of Nevada in Las Vegas.

Burroughs said that Facebook clearly knew live streams would help the company make money, as they keep users on Facebook longer, making advertisers happy. If Facebook hadn't also considered the possibility that live streams of crime or violence would inevitably appear alongside the positive stuff, "they weren't doing a good enough job researching implications for societal harm," Burroughs said.

EARNINGS RESULTS

Facebook also reported stronger-than-expected quarterly results on Wednesday, as has been its custom. The company earned $3.06 billion, or $1.04 per share, in the January-March period. That's up from 76 per cent from $1.74 billion, or 60 cents per share, a year earlier. Analysts polled by FactSet were expecting earnings of 87 cents per share.

Revenue grew 49 per cent to $8.03 billion from $5.38 billion. Analysts expected $7.83 billion.

Facebook had 1.94 billion monthly active users as of the end of March, up 17 per cent from a year earlier. Daily active users were 1.28 billion, on average, for the month of March.

FUNHOUSE MIRROR?

With a quarter of the world's population on it, Facebook can serve as a mirror for humanity, amplifying both the good and the bad -- the local fundraiser for a needy family and the murder-suicide in a faraway corner of the planet. But lately, it has gotten outsized attention for its role in the latter, whether that means allowing the spread of false news and government propaganda or videos of horrific crimes.

Videos livestreaming murder or depicting kidnapping and torture have made international headlines even when the crimes themselves wouldn't have, simply because they were on Facebook, visible to people who wouldn't have seen them otherwise.

As the company introduces even more new features, it will continue to grapple with the reality that they will not always be used for positive or even mundane purposes. From his interviews and Facebook posts, it appears that Zuckerberg is at least aware of this, even if his company doesn't always respond as quickly as outsiders would like.

"It's heartbreaking, and I've been reflecting on how we can do better for our community," Zuckerberg wrote on Wednesday about the recent videos.

It's a learning curve for Facebook. In November, for example, Zuckerberg called the idea that false news on Facebook influenced the U.S. election "crazy." A month later, the company introduced a slew of initiatives aimed at combating false news and supporting journalism. And just last week, it acknowledged that governments or others are using its social network to influence political sentiment in ways that could affect national elections.

WHAT TO DO

Zuckerberg said Facebook workers review "millions of reports" every week. In addition to removing videos of crime or getting help for someone who might hurt themselves, he said, the company's bulked-up reviewing force will "also help us get better at removing things we don't allow on Facebook like hate speech and child exploitation."

Wednesday's announcement is a clear sign that Facebook continues to need human reviewers to monitor content, even as it tries to outsource some of the work to software due in part to its sheer size and the volume of stuff people post.

It's not all up to Facebook, though. Burroughs said users themselves need to decide whether they want to look at violent videos posted on Facebook or to circulate them, for example. And he urged news organizations to consider whether each Facebook live-streamed murder is a story.

"We have to be careful that it doesn't become a kind of voyeurism," he said.