Cloud-based messaging app Telegram is once again available on the iOS App Store after it was removed for apparently violating Apple Inc.’s content rules.

Several Telegram users noticed on Wednesday that the app had suddenly disappeared from the App Store. A few suspected that the disappearance was simply an error, but others speculated that the removal could be related to Telegram’s attempt to “reinvent” the app with the recently announced Telegram X. It turned out that both theories were wrong, and Apple had actually pulled the app for an entirely different reason.

“We were alerted by Apple that inappropriate content was made available to our users and both apps were taken off the App Store,” Telegram founder and Chief Executive Pavel Durov said on Twitter. “Once we have protections in place we expect the apps to be back on the App Store.” Durov called Telegram’s removal a “minor issue” that would be resolved soon, and the app has since returned to the App Store after it was missing for only 24 hours.

Although Telegram is once again available, it’s still not clear exactly what caused its removal in the first place, and Durov did not elaborate on the “inappropriate content” that Apple found. Whatever the content was, it was most likely shared by users rather than by Telegram itself, and Apple has specific feature requirements in place for apps that handle user-generated content. These features include content filters, a reporting system, the ability to block abusive users and published contact information for the app’s developers.

“Apps with user-generated content or services that end up being used primarily for pornographic content, objectification of real people (e.g. ‘hot-or-not’ voting), making physical threats, or bullying do not belong on the App Store and may be removed without notice,” Apple says in its guidelines. “If your app includes user-generated content from a web-based service, it may display incidental mature ‘NSFW’ content, provided that the content is hidden by default and only displayed when the user turns it on via your website.”

Telegram’s end-to-end encryption and private chat features have made it popular with privacy-conscious users, but it has also been used by criminal and terrorist organizations for the same reasons. As a result, Telegram has fallen under government scrutiny in several countries, and Durov claimed last year that two U.S. agencies had attempted to bribe Telegram into providing secret back doors for law enforcement. “It would be naive to think you can run an independent/secure cryptoapp based in the U.S.,” Durov said at the time.

Earlier this month, reports surfaced that Telegram is considering a $500 million initial coin offering, and the company may set up internal app payments using its own cryptocurrency.

Photo: Telegram