The Kremlin issued the decree after the messaging app would not provide decryption keys to let Russian authorities snoop on what users were talking about -- seven percent of Telegram's 200 million users are in Russia, around 14 million people. Telegram decided user privacy was more important than kowtowing to Russia.
Durov says the block means Telegram was not able to fully prepare the app for this week's iOS 11.4 release. Some features, including stickers, do not work on the latest firmware.
Apple's kibosh on updates also means that Telegram was not able to make the app fully compliant with GDPR privacy rules in time for last week's deadline. It's not clear what that means for Telegram and its European users. But with hefty fines at stake for GDPR violations, Telegram could follow Instapaper and other services by temporarily suspending service in the EU until it can resolve the matter. There are significant implications for Telegram if Apple's block stays in place, though Durov says that his company is trying to fix the issue.