This week’s rapid rise of anonymous instant messaging app Sarahah in the Apple Store has raised quite a few eyebrows. Sarahah has spiked in popularity thanks to a core demographic of teens, who link Instagram and Snapchat to the app to tell other users what they really think about them.

But the app — whose name comes from the Arabic word for honesty and candor — has invited vitriol and fear for becoming a “breeding ground for hate,” with users complaining of death threats, negative comments on user appearance, and other forms of bullying.

The founder of the app, Zain al-Abidin Tawfiq, told Al-Jazeera the initial purpose of the app was to allow users to be ruthlessly honest with bosses about work, expanding it to social circles so that, according to Sarahah’s meta description in the app store, it can “[help] you in discovering your strengths and areas for improvement by receiving honest feedback from your employees and your friends in a private manner.”

Sound familiar? That’s because it is: Users have compared Sarahah to other apps like Whisper and Secret, whose cache is their ability to shield users from each other. The thinking is that ridding users of their identity promotes brutal honesty, encouraging social interaction that’s otherwise impossible with a face and name.

Yet that very brutal honesty is what makes anonymous messaging apps like Sarahah particularly dangerous as breeding grounds for bullying, says Ben Zhao, a professor computer science at the University of Chicago. In 2014, Zhao and his research team published a paper analyzing Whisper’s community of users.

The crux of the potential bullying problem on Sarahah, Zhao says, is who gets to use it. The fact that Sarahah is open to people messaging others at the surface seems to make it a safe space, in that you have to be connected to another user to message them. But if your identity goes rogue and is shared, you’re making yourself vulnerable to a whole group of users who don’t know you and have access to your life via Snapchat and Instagram.

Whisper recognized that as a problem early on and installed moderators to create a more positive experience, Zhao tells Inverse. “They really spent a lot of time and energy trying to reach out and be a good force,” he says, calling Yik Yak the “worst offender” in anonymous bullying. “They [Whisper] would try to engage and enforce an environment where bullying was minimized.”

It was in Whisper’s interests to create a safe space; Zhao and his team found that bullying ultimately drove users away, and Zhao says that’s what ultimately killed Yik Yak. Sarahah, however, hasn’t installed such a moderating force, and ultimately might be driven to become a bullying platform without the virtual version of an authority figure keeping users in line.

Anonymity on the internet affords users who might otherwise be perfectly nice and normal people to lash out and potentially be unimaginably mean, sneering, and menacing to others — particularly those they do not know. In 2004, psychologist John Suler published a groundbreaking paper saying as such, calling it the online disinhibition effect. Suler suggests that it’s not we devolve into terrible humans but rather that we create an alternate ego we justify as someone who lives exclusively online. In other words, people using anonymous messaging apps aren’t terrible, so much as capable of dissociating who they are on the internet from who they are in real life.

That’s where Sarahah’s psychological potential as a bullying platform gets messy, in that its linkage with Snapchat and Instagram is doubly dangerous: It targets teenagers who live their lives online, and blurs that separation of internet identity from real identity.

It remains to be seen whether Sarahah’s Snapchat and Instagram connection will lead it to Yik Yak’s fate or send it into Whisper territory. A study in March suggest that anonymous people build a sense of shared identity when they notice similarities or are confronted with a profile — much like that found in Sarahah. Trolls, bullies, haters, and their awful ilk take a step back when they know they have a profile, which — along with moderators — might ultimately keep Sarahah around.

Zhao says the history of anonymous messaging apps stands behind Sarahah. “Once you give people anonymity, they say all sorts of awful things,” he says. “If they [Sarahah] don’t correct this problem, I’d be surprised if it stuck around in its current form.”