An investigative report claims that Kik Messenger, an instant messaging app popular with children and teenagers, has become “the defacto app for grooming children online,” in part due to its ease of access to minors.

Kik Messenger is a free instant messaging service from Kik Interactive, a Canadian tech firm founded in 2009. Since then, it has gained over 300 million users and reaches 40 percent of teenagers in the United States. The report is a collaboration between British investigative media company Point and Forbes, which found that predators quickly move to contact and groom under-age users on the service, aided by third-party apps that help share profiles.

Point and Forbes found that Kik is frequently cited by law enforcement as a tool used by predators, with one official writing that the app is popular because “it is free, simple to set up, easily accessible, potentially anonymous and allows users to share digital data privately."

This isn’t the first time that Kik has been linked to crimes against children. In 2016, The New York Times reported that the app was becoming an increasing concern for law enforcement officials, with a number of instances where predators have used the app to exchange child pornography, to send explicit messages or arrange meetings with minors. At the time, Kik was working to take steps to “assist in preventing child exploitation,” which included posting a law enforcement guide and sponsoring an annual conference on crimes against children.

But that despite those efforts, Point and Forbes found that abuse on the app is still ongoing, finding “evidence of a vast number of child exploitation cases involving the use of Kik,” and that predators continue to use the app to target children. Reporters from the two publications posed as 13 and 14-year-old girl on the app, and within an hour of joining several public groups, the two profiles received numerous private messages from male users, including some with explicit language and images. The reporters then used a third-party app called KFF Username Finder For Kik, which helps boost one’s Kik profile. Within minutes of advertising their profiles on the app, they received hundreds of messages from other users. “Not only were many aggressive in tone, they also contained images of male genitalia.”

The report points out that Kik Interactive has made substantial efforts to mitigate abuse on its messaging app, and that predators are increasingly using a wide range of social media apps to target children. Kik has begun utilizing a tool called PhotoDNA that identifies reported images and video of child abuse, and frequently provides information to law enforcement to help with investigations. But problems remain: Point and Forbes spoke with child advocacy groups, which indicated that Kik could be doing more to combat abuse, such as adding more privacy controls and being more responsive to user complaints, and worryingly, haven’t removed profiles of users who have been charged and convicted of child abuse.

A spokesperson for Kik told Point and Forbes that safety was a priority for the company, and that it continues to invest in this area, but admitted that it can do a better job about proactively removing profiles that belong to users “who have been convicted of crimes related to child abuse.”

Kik is hardly alone when it comes to contending with abuse on its platform. Prominent social media companies such as Facebook, Twitter, and YouTube have been criticized for not doing enough to stop child abuse, harassment, and extremism on their respective platforms.