People demonstrate against sexual violence in Germany last summer. (Jörg Carstensen/AFP)

It was broadcast, live, to thousands of viewers: three men in an apartment, raping a young woman. The men could be heard saying, “You have been raped” and “Three against one,” according to Swedish newspaper Expressen.

The Facebook Live video was uploaded to a closed group of thousands of users on Sunday. Soon after, police began receiving calls from disturbed viewers, the paper reported. One woman told reporters that a man in the video “pulled off her clothes and lay on top of her.” According to BuzzFeed, the witness said she also saw one of the men pull out a gun and point it toward the camera, taunting viewers to “Come here, then.”

Others told reporters that the men in the video held the victim at gunpoint and forced her to say that she hadn't been attacked. Linda Johansson told Swedish Television News that one of the men “was putting the words in her mouth,” and that he “was very derisive and laughed throughout.”

As the police heard the reports, they asked that anyone who had seen the video make images available to law enforcement. According to Swedish Television News, hundreds likely saw the video, and images of the rape suspects were shared widely on social media.

On Monday, police arrested three men, ages 18, 20 and 24, in Uppsala, Sweden.

Christine Chen, a Facebook spokeswoman, told the New York Times that, “this is a hideous crime and we do not tolerate this kind of content on Facebook.” She added that, “if someone does violate our community standards while using Live, we want to interrupt these streams as quickly as possible when they’re reported to us. So we’ve given people a way to report violations during a live broadcast.”

Countries across Europe have been grappling with ways to fight sexual assault. A European Commission study last year found widespread disagreement on what counts as rape across the continent. In some countries, 55 percent of the population said that sex without consent is justifiable if a woman wears revealing clothing, flirts or gets drunk. Overall, 27 percent of Europeans agreed.

Lawmakers in some countries have responded by tightening their laws. Germany recently rewrote its relatively lax sexual assault laws. Now, if someone has sex with someone after they say “no,” that's rape even if the victim doesn't physically struggle. This week, the Irish government passed a new measure that would explicitly outlaw sex with someone who is passed-out drunk.

Under old Irish law, a rape has occurred if “a person has not consented to intercourse and/or if the perpetrator was reckless as to whether the victim did or did not consent.” That ambiguous wording left courts to determine exactly where the lines and limits were. The new law, legislators hope, clears up what should have already been obvious: that without vocal, continued consent, sex is rape.

Advocates for sexual assault victims have been pushing for stronger laws since the 1980s. But the issue faced new, intense scrutiny last year, when a rape case exploded in the media. A Polish national was found guilty of rape after he was caught “caressing and kissing” the neck of a woman who was passed out drunk at a bar. Video footage showed that the man had also unbuttoned the victim's pants. Police were summoned and when they woke the victim, she said she had never met the man.

In a victim impact report, the woman said: “Before the incident, I would have described myself as a positive person. I was horrified and extremely embarrassed to see the footage. I felt ashamed and angry with myself.”