More people are getting arrested for posting anonymous threats on social media

After reports of threats posted on the mobile app Yik Yak made students and faculty members nervous on the University of Missouri campus last week, the anonymous social-media platform is facing some pointed questions.

Three 19-year-old men have been charged with making terrorist threats against college campuses in Missouri on the app. Two of them specifically targeted black people, according to Reuters.

Yik Yak has made news before for the same reasons, with users posting inflammatory messages on its platform, usually targeting women as well as ethnic and LGBT groups. At times, harassment on the app has become almost as ubiquitous as the app itself, which enjoys some of its greatest popularity in the US on school campuses.

Yik Yak's representatives have pointed to its terms-of-service agreement to argue that measures are in place to handle anonymous threats. The agreement says in part: messages that "defame, abuse, harass, stalk, or threaten" people are prohibited.

The founders of Yik Yak published a blog post last week condemning the recent threats against the University of Missouri. It said, "This sort of misbehavior is NOT what Yik Yak is to be used for. Period."

There are built-in tools to moderate content. Users can flag messages by "downvoting" them. Posts that are downvoted five times are deleted. But civil-rights attorney Debbie Katz with the Washington, D.C.-based law firm Katz, Marshall & Banks says that's not enough.

"Their filters are ineffective," Katz said in a conversation with Business Insider. "Yik Yak needs to get more responsible about weeding out hate messages and not allow those hate messages to be published in the first place."

Katz's law firm has sent letters to Yik Yak founders Tyler Droll and Brooks Buffington seeking a meeting to discuss cyberbullying on the platform. Katz points to the scare at the University of Missouri last Tuesday as evidence that the anonymous threats "create an environment where college campuses feel less safe."

In an article earlier this year, Business Insider's Alyson Shontell wrote that someone posted a school shooting threat on the app in Alabama in February.

A sophomore student at Emory University did the same last month. Days apart, a teenager was arrested on suspicion of posting similar threats in Minnesota. The police accused the 17-year-old in that case of writing "guess who's gonna Columbine school" on Yik Yak.

Another student was due in court Monday after being charged with posting threats last week on Yik Yak that targeted black students at Michigan Technological University, Reuters reports.

Yik Yak says it cooperates with law enforcement when necessary, as is evident by the arrests of people who violate its terms of agreement by posting threats.

Still, Katz says Yik Yak should do more. Her law firm has sent letters to the Department of Education and to two of Yik Yak's investors, Sequoia Capital and Draper Fisher Jurvetson, citing the tens of millions of dollars invested in the app, and asking that they "behave responsibly" in addressing the app's cyberbullying problem.

Yik Yak's representatives tell Business Insider that the company tries to "encourage a positive and supportive community environment" on the app. They point to existing measures that allow users to flag questionable posts, which subjects those posts to immediate removal.

The representatives say Yik Yak is also "constantly working to enhance protective measures" on the platform, though Yik Yak would not go into detail on that.

Sufficiently mining social-media platforms for threats is no doubt tedious, but after threats against college campuses and specific threats against minorities, it's clear that these platforms should - and do - take them seriously.

And as we've seen with the South Carolina church shooter who killed nine people, and the Oregon community college shooter who also killed nine - and the massive terror attacks in Paris last week where warnings were reportedly lost in the shuffle, the consequences of missing overwhelming indications of a threat can indeed be deadly.