Popular microblogging platform Tumblr, popular with teenagers and college-aged youth, has been kicked off of the Apple App Store, allegedly over issues with “child sexual exploitation” being posted on the social network.

According to the Verge, the app, which has been on the store for several years, was removed on November 16 and has remained off the store since.

On Monday evening, it was confirmed that the reason was due to alleged problems with “child sexual exploitation and abuse” on the platform, which managed to slip through Tumblr’s filters.

“We continue to work to restore our app to the iOS App Store,” declared Tumblr in a statement. “We’re committed to helping build a safe online environment for all users, and we have a zero tolerance policy when it comes to media featuring child sexual exploitation and abuse. As this is an industry-wide problem, we work collaboratively with our industry peers and partners like NCMEC to actively monitor content uploaded to the platform.”

“Every image uploaded to Tumblr is scanned against an industry database of known child sexual abuse material, and images that are detected never reach the platform. A routine audit discovered content on our platform that had not yet been included in the industry database,” the company continued. “We immediately removed this content. Content safeguards are a challenging aspect of operating scaled platforms. We’re continuously assessing further steps we can take to improve and there is no higher priority for our team.”

The app is still available for Android on Google’s Play Store.

In 2017, a study revealed that nearly half of Tumblr users see porn while browsing, while in the same year, a lawyer accused the company of ignoring revenge porn posted to the platform after it allegedly took three weeks to get revenge porn featuring his 17-year-old client removed.