The FSB filed an administrative violation against Telegram for failing to submit “information required to decode the received, transmitted, delivered and (or) processed e-mails,” according to a Sept. 14 letter that Durov attached to his post on the VK social network.

Russia’s media censor, Roskomnadzor, began blocking messaging services that refuse to hand over information for the government’s “Register of Information Disseminators” last spring.

The register, a list of every website allowing the publication of user-generated content, was setup in 2014.

Durov told the Vedomosti newspaper that it was unclear whether the administrative violation report would lead to Telegram being blocked in Russia.

He cited lawyers as saying that these administrative charges could complicate his travels to and from Russia.

In his Telegram channel, Durov responded to Iran’s criminal case against him on charges of providing services to terrorists, saying he wished he could visit Iran, but that it was “more painful” to not visit Russia because of his parents.

“But Mom and Dad are not too old to travel and the globe is still pretty big.”